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The effects of Gymnema Sylvestre supplementation on lipid profile, glycemic control, blood pressure, and anthropometric indices in adults: A systematic review and meta-analysis
Abstract
There is a growing interest in the considerable health benefits of Gymnema Sylvestre (GS) supplementation, as some studies have reported that it may improve cardiometabolic risk factors. However, the widespread impact of GS supplementation on the parameters mentioned above is not fully resolved. Consequently, this study aimed to examine the effects of GS supplementation on lipid profile, glycemic control, blood pressure, and anthropometric indices in adults. Eligible randomized controlled trials (RCT), published up to November 2021, were identified through PubMed, Scopus, and ISI Web of Science databases. Six studies, were included and analyzed using a random-effects model to calculate weighted mean differences (WMDs) with 95% confidence intervals (CI). All studies were conducted in adults that used a GC supplement (> 1 week) and assessed our selected cardiovascular risk factors. Outcomes revealed that GS supplementation significantly decreased triglyceride (p < 0.001), total cholesterol (p < 0.001), low-density lipoprotein (p < 0.001), fasting blood sugar (p < 0.001), and diastolic blood pressure (p = 0.003). Some limitations, including notable heterogeneity, low quality of studies, and lack of diversity among research participants, should be considered when interpreting our results. Our outcomes suggest that GS supplementation may improve cardiovascular risk factors. Future large-high-quality RCTs with longer duration and various populations are needed to firmly establish the clinical efficacy of the plant.
... While Gymnema sylvestre-a species similar to G. inodorum-has been extensively studied for its phytochemical constituent as well as its therapeutic potential [5]; the latter remains underexplored despite its traditional use in the same regions. These plants contain significant phytoconstituents, including triterpene saponins (such as gymnemic acids), gymnemasaponins, and polyphenols. ...
The therapeutic potential of plant extracts has attracted significant interest, especially regarding indigenous species with health-promoting properties. Gymnema inodorum, native to Northern Thailand, is recognized for its rich phytochemical profile; however, the impact of various extraction techniques on its phenolic composition and bioactivity remains underexplored. Optimizing extraction methods is essential to enhance the pharmacological efficacy of this plant’s bioactive compounds. This study investigated the influence of four extraction methods—ethanol maceration, ethanol reflux, aqueous decoction, and microwave-assisted extraction—on the bioactive profile of G. inodorum leaves, with a focus on the phenolic content and biological activities. Antioxidant activities were evaluated using DPPH, ABTS, and FRAP assays, while the total phenolic and flavonoid contents were quantified by colorimetric methods. High-Performance Liquid Chromatography (HPLC) quantified gymnemic acid and key phenolic compounds. Among the methods, ethanol reflux yielded the highest antioxidant activities (DPPH and ABTS scavenging), with a total phenolic content of 82.54 mg GAE/g and flavonoid content of 31.90 mg QE/g. HPLC analysis identified sinapic acid, myricetin, and p-hydroxybenzoic acid as major phenolics. Furthermore, the ethanol reflux extract displayed potent anti-diabetic activity, with IC50 values of 13.36 mg/mL for α-amylase and 7.39 mg/mL for α-glucosidase, as well as strong anti-inflammatory activity (IC50 of 1.6 mg/mL) and acetylcholinesterase inhibition (IC50 of 1.2 mg/mL). These findings suggest that ethanol reflux extraction is a highly effective method for producing bioactive-rich G. inodorum extracts, with substantial pharmacological potential for developing herbal remedies and nutraceuticals, particularly in enhancing therapeutic approaches for diabetes and other health-related conditions.
... Plant has also been used to cure arthritis (Helms and Quan 2006), inflammation (Diwan et al. 1995), cancer (Kannabiran and Khanna 2009), and hepatotoxicity (Srividya et al. 1970). Studies have shown that G. sylvestre has several health benefits, including lowering blood pressure, triglycerides, total cholesterol, low-density lipoprotein, and fasting blood sugar (Zamani et al. 2022). By elevating the expression of cell survival pathways and the free radical scavenger system, G. sylvestre extracts defend against cytokine-induced apoptosis of β-cells (Al-Romaiyan et al. 2020). ...
Diabetes is a chronic disease that affects several organs and can be treated using phytochemicals found in medicinal plants. Gymnema sylvestre (Asclepiadaceae) is one such medicinal plant rich in anti-diabetic properties. The plant is commonly known as madhunashini in Sanskrit because of its ability to cure diabetes (sugar). Gymnemic acid (GA) is a phytochemical (a triterpenoid saponin) responsible for the herb’s main pharmacological activity. This secondary metabolite has a lot of potential as a phytochemical with pharmacological properties including nephroprotection, hypoglycemia, antioxidant, antimicrobial, and anti-inflammatory. Gymnema has acquired a lot of popularity in recent years due to its low side effects and high efficacy in healing diabetes, which has led to overexploitation by pharmaceutical enterprises for its biomass in the wild for the purification of gymnemic acid. Modern biotechnological techniques involving the establishment of cell and organ cultures from G. sylvestre will assist us in fulfilling the need for gymnemic acid production. The present review provides insights on the establishment of cell and organ cultures for the production of a potent antidiabetic molecule gymnemic acid. Further, the review also delves into the intricacies of the different strategies for improved production of gymnemic acid using various elicitors. There is huge potential for sustainable production of gymnemic acid which could be met by establishment of bioreactor scale production. Understanding and engineering the biosynthetic pathway could also lead to improved GA production.
ABSTRACT: We evaluated the effects of ketogenic diets (KDs) on body mass (BM), fat mass (FM), fat-free mass (FFM), body mass index (BMI), and body fat percentage (BFP) compared to non-KDs in individuals performing resistance training (RT). Online electronic databases including PubMed, the Cochrane Library, Web of Science, Embase, SCOPUS, and Ovid were searched to identify initial studies until February 2021. Data were pooled using both fixed and random-effects methods and were expressed as weighted mean difference (WMD) and 95% confidence intervals (CI). Out of 1372 studies, 13 randomized controlled trials (RCTs) that enrolled 244 volunteers were included. The pooled results demonstrated that KDs significantly decreased BM [(WMD ¼ À3.67 kg; 95% CI: À4.44, À2.90, p < 0.001)], FM [(WMD ¼ À2.21 kg; 95% CI: À3.09, À1.34, p < 0.001)], FFM [(WMD ¼ À1.26 kg; 95% CI: À1.82, À0.70, p < 0.001)], BMI [(WMD ¼ À1.37 kg.m À2 ; 95% CI: À2.14, À0.59, p ¼ 0.022)], and BFP [(WMD ¼ À2.27%; 95% CI: À3.63, À0.90, p ¼ 0.001)] compared to non-KDs. We observed beneficial effects of KDs compared to non-KDs on BM and body fat (both FM and BFP) in individuals performing RT. However, adherence to KDs may have a negative effect on FFM, which is not ameliorated by the addition of RT.
Objectives:
This study was performed to evaluate the long-term maintenance of nutritional changes promoted during an intensive initial intervention to induce body weight loss. The ability of these changes to predict long-term health outcomes was also examined.
Methods:
Nutritional variables, body composition, and metabolic markers collected in the RESOLVE project were analyzed before and after a 3-week intensive diet-exercise intervention (Phase 1), and during a subsequent supervision under free living conditions, of 12 months (Phase 2).
Results:
As expected, the macronutrient composition of the diet was modified to promote a negative energy balance during Phase 1. The decrease in carbohydrates imposed during this phase was maintained during Phase 2 whereas the increase in protein intake returned to baseline values at the end of the program. Dietary fiber intake was almost doubled during Phase 1 and remained significantly greater than baseline values throughout Phase 2. Moreover, fiber intake was the only nutritional variable that systematically and significantly predicted variations of health outcomes in the study.
Conclusion:
The adequacy of dietary fiber intake should be a matter of primary consideration in diet-based weight reduction programs.
The nutraceuticals market is vast, encompassing many different products with inconsistent levels of evidence available to support their use. This overview represents a Western perspective of the nutraceuticals market, with a brief comparison with that in China, as an illustration of how individual health supplements increase and decrease in popularity in regional terms. Recent changes in sales patterns, mainly taken from the US market, are summarized and a selection of five newer products, which have not been subject to extensive recent review are profiled: astaxanthin, a carotenoid found in red algae, seafood, salmon and trout, as an antioxidant; cannabidiol, a non‐euphoric marijuana ingredient used as mood enhancer and for painful/inflammatory conditions; modified extracts of ginseng used in new indications including dementia and space travel; monk fruit, a non‐sugar high intensity sweetener and nigella seed, a popular food ingredient and Asian medicine, which has experienced an extraordinary rise in sales recently.
Linked Articles
This article is part of a themed section on The Pharmacology of Nutraceuticals. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v177.6/issuetoc
Background
Patients with diabetes are at higher risk for death and cardiovascular outcomes than the general population. We investigated whether the excess risk of death and cardiovascular events among patients with type 2 diabetes could be reduced or eliminated.
Methods
In a cohort study, we included 271,174 patients with type 2 diabetes who were registered in the Swedish National Diabetes Register and matched them with 1,355,870 controls on the basis of age, sex, and county. We assessed patients with diabetes according to age categories and according to the presence of five risk factors (elevated glycated hemoglobin level, elevated low-density lipoprotein cholesterol level, albuminuria, smoking, and elevated blood pressure). Cox regression was used to study the excess risk of outcomes (death, acute myocardial infarction, stroke, and hospitalization for heart failure) associated with smoking and the number of variables outside target ranges. We also examined the relationship between various risk factors and cardiovascular outcomes.
Results
The median follow-up among all the study participants was 5.7 years, during which 175,345 deaths occurred. Among patients with type 2 diabetes, the excess risk of outcomes decreased stepwise for each risk-factor variable within the target range. Among patients with diabetes who had all five variables within target ranges, the hazard ratio for death from any cause, as compared with controls, was 1.06 (95% confidence interval [CI], 1.00 to 1.12), the hazard ratio for acute myocardial infarction was 0.84 (95% CI, 0.75 to 0.93), and the hazard ratio for stroke was 0.95 (95% CI, 0.84 to 1.07). The risk of hospitalization for heart failure was consistently higher among patients with diabetes than among controls (hazard ratio, 1.45; 95% CI, 1.34 to 1.57). In patients with type 2 diabetes, a glycated hemoglobin level outside the target range was the strongest predictor of stroke and acute myocardial infarction; smoking was the strongest predictor of death.
Conclusions
Patients with type 2 diabetes who had five risk-factor variables within the target ranges appeared to have little or no excess risk of death, myocardial infarction, or stroke, as compared with the general population. (Funded by the Swedish Association of Local Authorities and Regions and others.)
Black seed (Nigella sativa) is an annual flowering plant from Ranunculaceae family, native to southwest Asia. This plant has many food and medicinal uses. The use of its seeds and oil is common for treatment of many diseases, including rheumatoid arthritis, asthma, inflammatory diseases, diabetes and digestive diseases. The purpose of this study was to provide a comprehensive review on the scientific reports that have been published about N. sativa. The facts and statistics presented in this review article were gathered from the journals accessible in creditable databases such as Science Direct, Medline, PubMed, Scopus, EBSCO, EMBASE, SID and IranMedex. The keywords searched in Persian and English books on medicinal plants and traditional medicine, as well as the above reputable databases were “Black seed”, ”Nigella sativa“, “therapeutic effect”, and “medicinal plant”. The results showed that N. sativa has many biological effects such as anti-inflammatory, anti-hyperlipidemic, anti-microbial, anti-cancer, anti-oxidant, anti-diabetic, anti-hypertensive, and wound healing activities. It also has effects on reproductive, digestive, immune and central nervous systems, such as anticonvulsant and analgesic activities. In summary, it can be used as a valuable plant for production of new drugs for treatment of many diseases.
ABI
: ankle–brachial (blood pressure) index
ABPM
: ambulatory blood pressure monitoring
ACCORD
: Action to Control Cardiovascular Risk in Diabetes
ACE-I
: angiotensin-converting enzyme inhibitor
ACS
: acute coronary syndromes
ADVANCE
: Action in Diabetes and Vascular disease: PreterAx
Systematic reviews and meta-analyses represent the uppermost ladders in the hierarchy of evidence. Systematic reviews/meta-analyses suggest preliminary or satisfactory clinical evidence for agnus castus (Vitex agnus castus) for premenstrual complaints, flaxseed (Linum usitatissimum) for hypertension, feverfew (Tanacetum partenium) for migraine prevention, ginger (Zingiber officinalis) for pregnancy-induced nausea, ginseng (Panax ginseng) for improving fasting glucose levels as well as phytoestrogens and St John's wort (Hypericum perforatum) for the relief of some symptoms in menopause. However, firm conclusions of efficacy cannot be generally drawn. On the other hand, inconclusive evidence of efficacy or contradictory results have been reported for Aloe vera in the treatment of psoriasis, cranberry (Vaccinium macrocarpon) in cystitis prevention, ginkgo (Ginkgo biloba) for tinnitus and intermittent claudication, echinacea (Echinacea spp.) for the prevention of common cold and pomegranate (Punica granatum) for the prevention/treatment of cardiovascular diseases. A critical evaluation of the clinical data regarding the adverse effects has shown that herbal remedies are generally better tolerated than synthetic medications. Nevertheless, potentially serious adverse events, including herb-drug interactions, have been described. This suggests the need to be vigilant when using herbal remedies, particularly in specific conditions, such as during pregnancy and in the paediatric population. Copyright © 2016 John Wiley & Sons, Ltd.
Introduction:
Diabetes is a serious metabolic disorder and plenty of medical plants are used in traditional medicines to treat diabetes. These plants have no side effects and many existing medicines are derived from the plants. The purpose of this systematic review is to study diabetes and to summarize the available treatments for this disease, focusing especially on herbal medicine.
Methods:
Required papers about diabetes and effective plants were searched from the databases, including Science direct, PubMed, Wiley, Scopus, and Springer. Keywords in this study are "medicinal plants", "diabetes", "symptom", "herbal", and "treatment". Out of the 490 collected articles (published in the period between 1995 and 2015), 450 were excluded due to non-relevance or lack of access to the original article.
Results:
Diabetes is mainly due to oxidative stress and an increase in reactive oxygen species that can have major effects. Many plants contain different natural antioxidants, in particular tannins, flavonoids, C and E vitamins that have the ability to maintain β-cells performance and decrease glucose levels in the blood.
Conclusion:
According to published results, it can be said that medical plants are more affordable and have less side effects compared synthetic drugs, and are more effective in treatment of diabetes mellitus.
Systematic reviews and meta-analyses have become increasingly important in health care. Clinicians read them to keep up to date with their field [1],[2], and they are often used as a starting point for developing clinical practice guidelines. Granting agencies may require a systematic review to ensure there is justification for further research [3], and some health care journals are moving in this direction [4]. As with all research, the value of a systematic review depends on what was done, what was found, and the clarity of reporting. As with other publications, the reporting quality of systematic reviews varies, limiting readers' ability to assess the strengths and weaknesses of those reviews.
Several early studies evaluated the quality of review reports. In 1987, Mulrow examined 50 review articles published in four leading medical journals in 1985 and 1986 and found that none met all eight explicit scientific criteria, such as a quality assessment of included studies [5]. In 1987, Sacks and colleagues [6] evaluated the adequacy of reporting of 83 meta-analyses on 23 characteristics in six domains. Reporting was generally poor; between one and 14 characteristics were adequately reported (mean = 7.7; standard deviation = 2.7). A 1996 update of this study found little improvement [7].
In 1996, to address the suboptimal reporting of meta-analyses, an international group developed a guidance called the QUOROM Statement (QUality Of Reporting Of Meta-analyses), which focused on the reporting of meta-analyses of randomized controlled trials [8]. In this article, we summarize a revision of these guidelines, renamed PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses), which have been updated to address several conceptual and practical advances in the science of systematic reviews (Box 1).
Box 1: Conceptual Issues in the Evolution from QUOROM to PRISMA
Completing a Systematic Review Is an Iterative Process
The conduct of a systematic review depends heavily on the scope and quality of included studies: thus systematic reviewers may need to modify their original review protocol during its conduct. Any systematic review reporting guideline should recommend that such changes can be reported and explained without suggesting that they are inappropriate. The PRISMA Statement (Items 5, 11, 16, and 23) acknowledges this iterative process. Aside from Cochrane reviews, all of which should have a protocol, only about 10% of systematic reviewers report working from a protocol [22]. Without a protocol that is publicly accessible, it is difficult to judge between appropriate and inappropriate modifications.
Cardiovascular disease risk factor control as primary prevention in patients with type 2 diabetes mellitus has changed substantially in the past few years. The purpose of this scientific statement is to review the current literature and key clinical trials pertaining to blood pressure and blood glucose control, cholesterol management, aspirin therapy, and lifestyle modification. We present a synthesis of the recent literature, new guidelines, and clinical targets, including screening for kidney and subclinical cardiovascular disease for the contemporary management of patients with type 2 diabetes mellitus.
© 2015 by the American Diabetes Association and the American Heart Association, Inc.
Aim: The purpose of the study was to investigate the effect of different compounds from leaves of Gymnema sylvestre (GS) on nitric oxide (NO) production. Materials and Methods: To study the binding and effect of different compounds from GS 10 molecules were docked on the enzyme endothelial NO synthase (eNOS) using molegro virtual docker and the result was compared with that of the agonists (acetylcholine, bradykinin, and serotonin). Further to confirm the activity animal studies were done on albino rats blood glucose levels were measured using glucometer and NO levels were estimated spectrophotometrically using griess agent. Results: Docking studies showed that almost all the compounds from the leaves of GS bind perfectly with eNOS with the lowest binding energies similar to that of the agonists. Animal studies confirmed the docking results when blood glucose levels decreased and NO levels increased in diabetic rats treated with GS leaf extract. Conclusion: Docking and animal studies show that leaf extract of GS might help in improving the production of NO by stimulating eNOS and thus, can be used as an agent to avoid diabetes and diabetic vascular complications.
Obesity is associated with numerous co-morbidities such as cardiovascular diseases, type 2 diabetes, hypertension and others. Therefore, the present study was planned to investigate the effect of water- soluble fraction of Gymnema sylvestre ethanol extract on biochemical and molecular alterations in obese diabetic rats. Diabetes was induced by single i.v. injection of streptozotocin (45 mg/kg) via tail vein. Obesity was induced by oral feeding of high fat diet for a period of 28 days in diabetic rats. Body weight gain, food intake, water intake, hemodynamic parameters (systolic, diastolic, mean arterial blood pressures and heart rate), serum biochemical parameters (leptin, insulin, lipid levels, apolipoprotein B and glucose), cardiomyocyte apoptosis (cardiac caspase-3, Na(+)/K(+) ATPase activity and DNA fragmentation) organs and visceral fat pad weight and oxidative stress parameters were measured. Oral treatment with water soluble fraction of Gymnema sylvestre ethanol extracts (120 mg/kg/p.o.) for a period of 21 days, resulted in significant reduction in heart rate, mean arterial pressure, serum leptin, insulin, apolipoprotein B, lipids, glucose, cardiac caspase-3 levels, Na(+)/K(+) ATPase activity and DNA laddering, visceral fat pad and organ's weight and improved the antioxidant enzymes levels in the high fat diet induced obesity in diabetic rats. The results of present study reveal that water soluble fraction of Gymnema sylvestre ethanol extract could be useful intervention in the treatment of obesity and type-2 diabetes mellitus.
Diabetes mellitus is a chronic condition that occurs when the body cannot produce enough or effectively use of insulin. Compared with individuals without diabetes, patients with type 2 diabetes mellitus have a considerably higher risk of cardiovascular morbidity and mortality, and are disproportionately affected by cardiovascular disease. Most of this excess risk is it associated with an augmented prevalence of well-known risk factors such as hypertension, dyslipidaemia and obesity in these patients. However the improved cardiovascular disease in type 2 diabetes mellitus patients can not be attributed solely to the higher prevalence of traditional risk factors. Therefore other non-traditional risk factors may be important in people with type 2 diabetes mellitus. Cardiovascular disease is increased in type 2 diabetes mellitus subjects due to a complex combination of various traditional and non-traditional risk factors that have an important role to play in the beginning and the evolution of atherosclerosis over its long natural history from endothelial function to clinical events. Many of these risk factors could be common history for both diabetes mellitus and cardiovascular disease, reinforcing the postulate that both disorders come independently from "common soil". The objective of this review is to highlight the weight of traditional and non-traditional risk factors for cardiovascular disease in the setting of type 2 diabetes mellitus and discuss their position in the pathogenesis of the excess cardiovascular disease mortality and morbidity in these patients.
Gymnema sylvestre R. Br. (G. sylvestre) belonging to the family Asclepiadaceae, has been used as a traditional medicine plant in Africa, Australia and Asia especially in India.Aim of the studyThe present study aimed to clarify the effect of G. sylvestre leaves extract on several physiological parameters of diabetic rats.Materials and methodsG. sylvestre leaves extract (18 mg/kg body weight) was orally administered for 30 days to normal and streptozotocin (STZ) diabetic rats.ResultsSTZ-diabetic rats exhibited a significant increase in plasma glucose, liver function enzymes [alanine aminotransaminase (ALT) and aspartate aminotransaminase (AST)], triglycerides, total cholesterol, LDL-cholesterol malondialdehyde, catalase, reduced glutathione and a significant decrease in insulin, HDL-cholesterol and erythrocyte superoxide dismutase levels. Treatment diabetic rats with G. sylvestre leaves extract significantly decreased plasma glucose, ALT, AST, triglycerides, total cholesterol, LDL-cholesterol, malondialdehyde and significantly increased insulin, HDL-cholesterol and erythrocyte superoxide dismutase levels compared to untreated diabetic rats.Conclusion
It could be concluded that G. sylvestre leaves extract treated diabetic rats’ complications including hyperglycemia, hypoinsulinemia, hyperlipidemia and oxidative stress.
Gymnema sylvestre is a natural herb. The present study was conducted to study the effect of gurmar leaf powder intervention on the blood glucose level of 20 non-insulin dependent diabetic women, (40-60) years residing in the Udaipur city, Rajasthan. Subjects selected were taking no oral hypoglycemic drug (i.e. newly diagnosed) and were willing to participate in the intervention study. Information regarding name, age, religion, lifestyle pattern, was collected with the help of interview schedule. Anthropometric parameters were collected prior to intervention to assess the nutritional status. Blood glucose levels were assessed before and after intervention period by using one touch horizon glucometer. Everyday 6 gm of gurmar leaf powder was used to intervene the subjects in three divided doses. Dietary survey using 24 hours recall method was also done. (3 days- once in a week). Results of intervention revealed that gurmar leaf powder had positive and encouraging effects over blood glucose levels. No adverse effect was observed on the health status of the subjects and it can thus be concluded that gurmar powder is effective in lowering the fasting as well as postprandial blood glucose levels.
Obesity plays a central role in the insulin resistance syndrome, which is associated with hyperinsulinemia, hypertension, hyperlipidemia, type 2 diabetes mellitus, and an increased risk of atherosclerotic cardiovascular disease. The present study was done to assess the effect of Gymnema sylvestre extract (GSE) in the high fat diet (HFD)-induced cellular obesity and cardiac damage in Wistar rats.
Adult male Wistar rats (150-200 g body weight) were used in this study. HFD was used to induce obesity. Body mass index, hemodynamic parameters, serum leptin, insulin, glucose, lipids, apolipoprotein levels, myocardial apoptosis, and antioxidant enzymes were assessed. Organ and visceral fat pad weights and histopathological studies were also carried out.
Oral feeding of HFD (20 g/day) for a period of 28 days resulted in a significant increase in body mass index, organ weights, visceral fat pad weight, cardiac caspase-3, cardiac DNA laddering (indicating apoptotic inter-nucleosomal DNA fragment), and lipid peroxide levels of cardiac tissues of rats. Further, mean arterial blood pressure, heart rate, serum leptin, insulin, LDH, LDL-C, total cholesterol, triglycerides, and apolipoprotein-B levels were enhanced significantly, whereas serum HDL-C, apoliporotein-A1 levels, and cardiac Na(+) K(+) ATPase, antioxidant enzymes levels were significantly decreased. Furthermore, treatment with standardized ethanolic GSE (200 m/kg/p.o.) for a period of 28 days resulted in significant reversal of above mentioned changes in the obese Wistar rats.
The present study has demonstrated the significant antiobesity potential of GSE in murine model of obesity.
Objective: Funnel plots (plots of effect estimates against sample size) may be useful to detect bias in meta-analyses that were later contradicted by large trials. We examined whether a simple test of asymmetry of funnel plots predicts discordance of results when meta-analyses are compared to large trials, and we assessed the prevalence of bias in published meta-analyses. Design: Medline search to identify pairs consisting of a meta-analysis and a single large trial (concordance of results was assumed if effects were in the same direction and the meta-analytic estimate was within 30
Flaws in the design, conduct, analysis, and reporting of randomised trials can cause the effect of an intervention to be underestimated or overestimated. The Cochrane Collaboration’s tool for assessing risk of bias aims to make the process clearer and more accurate
To assess the association between high but nondiabetic blood glucose levels and the risk of death from all causes, coronary heart disease (CHD), cardiovascular disease, and neoplasms.
We studied the 20-year mortality of non-diabetic, working men, age 44-55 years, in three European cohorts known as the Whitehall Study (n = 10,025), the Paris Prospective Study (n = 6,629), and the Helsinki Policeman Study (n = 631). These men were identified by their 2-h glucose levels following an oral glucose tolerance test and by the absence of a prior diagnosis of diabetes. As the protocol for the oral glucose tolerance test and methods for measuring glucose differed between studies, mortality was analyzed according to the percentiles of the 2-h and fasting glucose distributions, using the Cox's proportional hazards model.
Men in the upper 20% of the 2-h glucose distributions and those in the upper 2.5% for fasting glucose had a significantly higher risk of all-cause mortality in comparison with men in the lower 80% of these distributions, with age-adjusted hazard ratios of 1.6 (95% CI 1.4-1.9) and 2.0 (1.6-2.6) for the upper 2.5%. For death from cardiovascular and CHD, men in the upper 2.5% of the 2-h and fasting glucose distributions were at higher risk, with age-adjusted hazard ratios for CHD of 1.8 (1.4-2.4) and 2.7 (1.7-4.4), respectively.
If early intervention aimed at lowering blood glucose concentrations can be shown to reduce mortality, it may be justified to lower the levels of both 2-h and fasting glucose, which define diabetes.
Many plant-based products have been suggested as potential antidiabetic agents, but few have been shown to be effective in treating the symptoms of Type 2 diabetes mellitus (T2DM) in human studies, and little is known of their mechanisms of action. Extracts of Gymnema sylvestre (GS) have been used for the treatment of T2DM in India for centuries. The effects of a novel high molecular weight GS extract, Om Santal Adivasi, (OSA(R)) on plasma insulin, C-peptide and glucose in a small cohort of patients with T2DM are reported here. Oral administration of OSA(R) (1 g/day, 60 days) induced significant increases in circulating insulin and C-peptide, which were associated with significant reductions in fasting and post-prandial blood glucose. In vitro measurements using isolated human islets of Langerhans demonstrated direct stimulatory effects of OSA(R) on insulin secretion from human ß-cells, consistent with an in vivo mode of action through enhancing insulin secretion. These in vivo and in vitro observations suggest that OSA(R) may provide a potential alternative therapy for the hyperglycemia associated with T2DM.
Funnel plots (plots of effect estimates against sample size) may be useful to detect bias in meta-analyses that were later contradicted by large trials. We examined whether a simple test of asymmetry of funnel plots predicts discordance of results when meta-analyses are compared to large trials, and we assessed the prevalence of bias in published meta-analyses.
Medline search to identify pairs consisting of a meta-analysis and a single large trial (concordance of results was assumed if effects were in the same direction and the meta-analytic estimate was within 30% of the trial); analysis of funnel plots from 37 meta-analyses identified from a hand search of four leading general medicine journals 1993-6 and 38 meta-analyses from the second 1996 issue of the Cochrane Database of Systematic Reviews.
Degree of funnel plot asymmetry as measured by the intercept from regression of standard normal deviates against precision.
In the eight pairs of meta-analysis and large trial that were identified (five from cardiovascular medicine, one from diabetic medicine, one from geriatric medicine, one from perinatal medicine) there were four concordant and four discordant pairs. In all cases discordance was due to meta-analyses showing larger effects. Funnel plot asymmetry was present in three out of four discordant pairs but in none of concordant pairs. In 14 (38%) journal meta-analyses and 5 (13%) Cochrane reviews, funnel plot asymmetry indicated that there was bias.
A simple analysis of funnel plots provides a useful test for the likely presence of bias in meta-analyses, but as the capacity to detect bias will be limited when meta-analyses are based on a limited number of small trials the results from such analyses should be treated with considerable caution.
The relation between pesticides exposure and metabolic syndrome (MetS) has not been clearly identified. Performing a systematic review and meta-analysis, PubMed, Cochrane Library, Embase, and ScienceDirect were searched for studies reporting the risk of MetS following pesticides exposure and their contaminants. We included 12 studies for a total of 6789 participants, in which 1981 (29.1%) had a MetS. Overall exposure to pesticides and their contaminants increased the risk of MetS by 30% (95CI 22%–37%). Overall organochlorine increased the risk of MetS by 23% (14–32%), as well as for most types of organochlorines: hexachlorocyclohexane increased the risk by 53% (28–78%), hexachlorobenzene by 40% (0.01–80%), dichlorodiphenyldichloroethylene by 22% (9–34%), dichlorodiphenyltrichloroethane by 28% (5–50%), oxychlordane by 24% (1–47%), and transnonchlor by 35% (19–52%). Sensitivity analyses confirmed that overall exposure to pesticides and their contaminants increased the risk by 46% (35–56%) using crude data or by 19% (10–29%) using fully-adjusted model. The risk for overall pesticides and types of pesticides was also significant with crude data but only for hexachlorocyclohexane (36% risk increase, 17–55%) and transnonchlor (25% risk increase, 3–48%) with fully-adjusted models. Metaregressions demonstrated that hexachlorocyclohexane increased the risk of MetS in comparison to most other pesticides. The risk increased for more recent periods (Coefficient = 0.28, 95CI 0.20 to 0.37, by year). We demonstrated an inverse relationship with body mass index and male gender. In conclusion, pesticides exposure is a major risk factor for MetS. Besides organochlorine exposure, data are lacking for other types of pesticides. The risk increased with time, reflecting a probable increase of the use of pesticides worldwide. The inverse relationship with body mass index may signify a stockage of pesticides and contaminants in fat tissue.
This systematic review and meta‐analysis aims to find the effect of Gymnema sylvestre (GS) supplementation on glycemic control in type‐2 diabetes mellitus (T2DM). PubMed, Cochrane library, Google Scholar, and Science Direct were searched from inception to June 2020 to identify the studies that reported GS supplementation on glycemic parameters. Standardized mean difference (SMD) was calculated by comparing the post‐intervention data with baseline data. SMDs with 95% confidence intervals (CIs) were pooled using a random‐effects model. Our meta‐analysis consisting of 10 studies with a total of 419 participants showed that GS supplementation significantly reduces fasting blood glucose (FBG) (SMD 1.57 mg/dl, 95% CI 2.22 to −0.93, p < .0001, I2 90%), postprandial blood glucose (PPBG) (SMD 1.04 mg/dl, 95% CI 1.53 to −0.54, p < .0001, I2 80%), and glycated haemoglobin (HbA1c) (SMD 3.91, 95% CI 7.35 to −0.16%, p < .0001, I2 99%) compared to baseline. Further, our study also found that GS significantly reduces triglycerides (SMD 1.81 mg/dl, 95% CI 2.95 to −0.66, p < .0001, I2: 96%), and total cholesterol (SMD 4.10 mg/dl, 95% CI 7.21 to −0.99, p < .0001, I2: 98%) compared to baseline. Our study shows that GS supplementation is effective in improving glycemic control and reducing lipid levels in T2DM patients and suggests that such supplementation might be used as an effective therapy for the management of T2DM and its associated complications to an extent.
Context:
Elevated serum concentrations of chemerin is a significant factor in the development of metabolic disorders.
Objective:
This systematic review and meta-analysis evaluated the influence of exercise training on serum concentrations of chemerin in patients with metabolic diseases.
Methods:
Thirteen studies including 463 participants were included and analysed using a random-effects model to calculate weighted mean differences with 95% confidence intervals.
Results:
Results indicated that exercise training significantly decreased serum concentrations of chemerin in patients with metabolic diseases when compared with controls. Subgroup analysis showed that exercise training resulted in decreases in serum concentrations of chemerin in men, however, this was not significant in women. Moreover, subgroup analyses based on the type of exercise did not reveal differential effects on serum concentrations of chemerin.
Conclusion:
Exercise training may produce improvements in serum concentrations of chemerin in patients with metabolic diseases. Further longer-term studies are needed to confirm these findings.
Gymnema sylvestre, a plant typical of India, has long been known for its hypoglycemic effects. The objective of this study was to evaluate the effect of G. sylvestre administration on glycemic control, insulin secretion, and insulin sensitivity in patients with impaired glucose tolerance (IGT). A randomized, double-blind, placebo-controlled clinical trial was conducted in 30 patients with IGT. Fifteen patients randomly received G. sylvestre in doses of 300 mg b.i.d. and the other 15 received placebo in the same way. Before and after the intervention, anthropometric and metabolic measurements were taken, including 2-h oral glucose tolerance test (2-h OGTT), fasting plasma glucose, glycated hemoglobin A1c (A1C), and the lipid profile panel. Areas under the curve of glucose and insulin were calculated, as well as the insulinogenic, Stumvoll, and Matsuda indices. Wilcoxon, Mann-Whitney U, and chi-square or Fisher's exact tests were performed, and a P-value ≤.05 was considered statistically significant. There was a significant reduction in 2-h OGTT (9.1 ± 1.2 vs. 7.8 ± 1.7 mmol/L, P = .003), A1C (5.8 ± 0.3% vs. 5.4 ± 0.4%, P = .025), body weight, body mass index, and low-density lipoprotein cholesterol levels in the G. sylvestre group, with an increment in the Matsuda index (1.8 ± 0.8 vs. 2.4 ± 1.2, P = .008). At the end of the intervention, 46.7% of the patients obtained normal values in A1C. In conclusion, G. sylvestre administration in patients with IGT decreased 2-h OGTT and A1C, increasing insulin sensitivity. There were also improvements in anthropometric measures and the lipid profile.
The aim of this study was to manage diabetes with medicinal plants (Gymnema sylvestre, Artemisia absinthium and Citillus colocynthis) in human patients with type II diabetes. Thirty two patients of type II diabetes from both sexes of 30-60 years age were registered for this study and distributed them into four groups, each having 8 patients. Capsules of each, Gymnema sylvestre, Artemisia absinthium and Citrullus colocynthis were given to patients twice a day for 30 days in 1 g per day dosage and investigated for glucose, triglyceride (TGL) and cholesterol level. Gymnema sylvestre reduced 37% glucose, 5% TGL, 13% cholesterol and 19% low desity lipoproteins (LDL) level in diabetic individuals. Citrullus colocynth reduced glucose, cholesterol and TGL and HDL-cholesterol level by 35, 6, 6, and 5%, respectively. Artemisia absinthium reduced 3% high desity lipoproteins (HDL) and 6% LDL level. From results, it can be concluded that the powdered Gymnema sylvestre, Citrulus colocynthis, and Artemisia absinthium possess good anti-diabetic features, however these herbal products had no significant effect on lipid profiles of the diabetic human.
Artemisia absinthium L., Citrullus colocynthis (L.) Schrad. and Gymnema sylvestre (Retz.) R.Br. ex Sm. have been used in Asian countries for thousands of years to treat diabetes. This study was conducted to evaluate hypoglycemic and antihyperlipidemic effects in type II hyperlipidemic diabetic patients. Study is blind randomized placebo-controlled clinical trials over 40 days. Individuals were divided randomly into 4 groups 1, 2, 3 & 4. Ten individuals were in each group. Group 1 was allocated for G. sylvestre, 2 for A. absinthium, 3 for C. colocynthis and 4 for placebo. Medication (1.0 g/day) was administered for 40 days. From each individual of each group on day 0, 10, 20, 30 and 40 blood samples were collected in fasting condition. Serum glucose values in group 1 dropped most considerably (p < 0.05). Diabetic individuals of all 3 groups as compared to control and placebo group, showed significantly lowered fasting serum glucose level (p < 0.05). Fasting serum triglycerides, cholesterol, HDL-cholesterol and LDL-cholesterol of all 3 groups were not reduced significantly at (p < 0.05) as compared to control and placebo groups. So it may be suggested that a type II diabetic patient can safely be switched from costly conventional antidiabetic medicine to cheap natural products. © 2018, National Institute of Science Communication and Information Resources (NISCAIR). All rights reserved.
Gymnema sylvestre is a medicinal plant whose consumption has demonstrated benefits on lipid and glucose levels, blood pressure, and body weight (BWt). The aim of this study was to evaluate the effect of G. sylvestre administration on metabolic syndrome (MetS), insulin secretion, and insulin sensitivity. A randomized, double-blind, placebo-controlled clinical trial was carried out in 24 patients (without pharmacological treatment), 30-60 years old, with diagnosis of MetS in accordance with the modified International Diabetes Federation criteria. Patients were randomly assigned to receive G. sylvestre or placebo twice daily before breakfast and dinner in 300 mg capsules for a total of 600 mg per day for 12 weeks. Before and after the intervention, the components of MetS were evaluated as well as BWt, body mass index (BMI), total cholesterol, low-density lipoprotein cholesterol, and very low-density lipoprotein (VLDL). Area under the curve of glucose and insulin, phases of insulin secretion, and insulin sensitivity were calculated. Statistical analysis was performed using Wilcoxon signed-rank, Mann-Whitney U, and chi-square tests; P ≤ .05 was considered statistically significant. After G. sylvestre administration, significant decreases in BWt (81.3 ± 10.6 kg vs. 77.9 ± 8.4 kg, P = .02), BMI (31.2 ± 2.5 kg/m(2) vs. 30.4 ± 2.2 kg/m(2), P = .02), and VLDL levels (0.45 ± 0.15 mmol/dL vs. 0.35 ± 0.15 mmol/dL, P = .05) were observed, without modifying the components of MetS, insulin secretion, and insulin sensitivity. In conclusion, G. sylvestre administration decreased BWt, BMI, and VLDL levels in subjects with MetS, without changes in insulin secretion and insulin sensitivity.
Importance:
Patients with type 2 diabetes are at high risk of cardiovascular disease (CVD) in part owing to hypertriglyceridemia and low high-density lipoprotein cholesterol. It is unknown whether adding triglyceride-lowering treatment to statin reduces this risk.
Objective:
To determine whether fenofibrate reduces CVD risk in statin-treated patients with type 2 diabetes.
Design, setting, and participants:
Extended posttrial follow-up of the Action to Control Cardiovascular Risk in Diabetes (ACCORD) Lipid Study participants between July 2009 and October 2014. An additional 5 years of follow-up were completed for a total of 9.7 years at general community and academic outpatient research clinics in the United States and Canada. Four thousand six hundred forty-four surviving ACCORD Lipid Trial participants of the original 5518 were selected based on the presence of type 2 diabetes and either prevalent CVD or CVD risk factors and high-density lipoprotein levels less than 50 mg/dL (<55 mg/dL for women and African American individuals).
Interventions:
Passive follow-up of study participants previously treated with fenofibrate or masked placebo.
Main outcomes and measures:
Occurrence of cardiovascular outcomes including primary composite outcome of fatal and nonfatal myocardial infarction and stroke in all participants and in prespecified subgroups.
Results:
The 4644 follow-on study participants were broadly representative of the original ACCORD study population and included significant numbers of women (n = 1445; 31%), nonwhite individuals (n = 1094; 21%), and those with preexisting cardiovascular events (n = 1620; 35%). Only 4.3% of study participants continued treatment with fenofibrate following completion of ACCORD. High-density lipoprotein and triglyceride values rapidly equalized among participants originally randomized to fenofibrate or placebo. Over a median total postrandomization follow-up of 9.7 years, the hazard ratio (HR) for the primary study outcome among participants originally randomized to fenofibrate vs placebo (HR, 0.93; 95% CI, 0.83-1.05; P = .25) was comparable with that originally observed in ACCORD (HR, 0.92; 95% CI, 0.79-1,08; P = .32). Despite these overall neutral results, we continued to find evidence that fenofibrate therapy effectively reduced CVD in study participants with dyslipidemia, defined as triglyceride levels greater than 204 mg/dL and high-density lipoprotein cholesterol levels less than 34 mg/dL (HR, 0.73; 95% CI, 0.56-0.95).
Conclusions and relevance:
The continued observation of heterogeneity of treatment response by baseline lipids suggests that fenofibrate therapy may reduce CVD in patients with diabetes with hypertriglyceridemia and low high-density lipoprotein cholesterol.
Trial registration:
clinicaltrials.gov Identifier: NCT00000620.
Objectives:
To estimate the impact of small reductions in the population distribution of diastolic blood pressure (DBP), such as those potentially achievable by population-wide lifestyle modification, on incidence of coronary heart disease (CHD) and stroke.
Design:
Published data from the Framingham Heart Study, a longitudinal cohort study, and from the National Health and Nutrition Examination Survey II, a national population survey, were used to examine the impact of a population-wide strategy aimed at reducing DBP by an average of 2 mm Hg in a population including normotensive subjects.
Setting/Participants:
White men and women aged 35 to 64 years in the United States.
Main Outcome Measures:
Incidence of CHD and stroke, including transient ischemic attacks (TIAs).
Results:
Data from overviews of observational studies and randomized trials suggest that a 2—mm Hg reduction in DBP would result in a 17% decrease in the prevalence of hypertension as well as a 6% reduction in the risk of CHD and a 15% reduction in risk of stroke and TIAs. From an application of these results to US white men and women aged 35 to 64 years, it is estimated that a successful population intervention alone could reduce CHD incidence more than could medical treatment for all those with a DBP of 95 mm Hg or higher. It could prevent 84% of the number prevented by medical treatment for all those with a DBP of 90 mm Hg or higher. For stroke (including TIAs), a population-wide 2—mm Hg reduction could prevent 93% of events prevented by medical treatment for those with a DBP of 95 mm Hg or higher and 69% of events for treatment for those with a DBP of 90 mm Hg or higher. A combination strategy of both a population reduction in DBP and targeted medical intervention is most effective and could double or triple the impact of medical treatment alone. Adding a population-based intervention to existing levels of hypertension treatment could prevent an estimated additional 67 000 CHD events (6%) and 34 000 stroke and TIA events (13%) annually among all those aged 35 to 64 years in the United States.
Conclusions:
A small reduction of 2 mm Hg in DBP in the mean of the population distribution, in addition to medical treatment, could have a great public health impact on the number of CHD and stroke events prevented. Whether such DBP reductions can be achieved in the population through lifestyle interventions, in particular through sodium reduction, depends on the results of ongoing primary prevention trials as well as the cooperation of the food industry, government agencies, and health education professionals.(Arch Intern Med. 1995;155:701-709)
IntroductionIndividual studiesThe summary effectHeterogeneity of effect sizesSummary points
Five water-soluble polysaccharides, including GSP11 (xylose:glucose = 1:2.47), GSP22 (rhamnose:glucose:galactose = 1.6:1:1.22), GSP33 (rhamnose:glucose:galactose = 1:1.5:1.1), GSP44 (xylose:glucose:galactose = 1:1.03:1.2) and GSP55 (rhamnose:xylose:glucose:galactose = 1:1.21:1.81:2.58), were obtained from Gymnema sylvestre and tested for their immunological and anti-tumor activities. The molecular weights of the five water-soluble polysaccharides were 5.3 × 104, 5.4 × 105, 9.5 × 105, 1.0 × 106 and 1.9 × 106 Da, respectively. Immunological activity tests revealed that both crude and deproteinated polysaccharides (GPS) possess good immunological activities, especially on blood serum hemolysin formation at 300 mg/kg. MTT assays revealed that all samples possessed anti-tumor activities in a dose-dependent manner except for GSP22 in AGS cells. At a concentration of 640 μg/mL, GSP11 and GSP33 showed good activities in U937 cells, with inhibitory rates of 78.6% and 83.8%, respectively, and GSP22 showed good activity in SGC cells with an inhibitory rate of 78.2%.
Michael Mitchell’s Interpreting and Visualizing Regression Models Using Stata is a clear treatment of how to carefully present results from model-fitting in a wide variety of settings. It is a boon to anyone who has to present the tangible meaning of a complex model in a clear fashion, regardless of the audience. As an example, many experienced researchers start to squirm when asked to give a simple explanation of the practical meaning of interactions in nonlinear models such as logistic regression. The techniques presented in Mitchell's book make answering those questions easy. The overarching theme of the book is that graphs make interpreting even the most complicated models containing interaction terms, categorical variables, and other intricacies straightforward.
Leaves of the Gymnema sylvestre (GS) plant have been used to treat diabetes mellitus for millennia, but the previously documented insulin secretagogue effects of GS extracts in vitro may be non-physiological through damage to the β-cells. We have now examined the effects of a novel GS extract (termed OSA) on insulin secretion from the MIN6 β-cell line and isolated human islets of Langerhans. Insulin secretion from MIN6 cells was stimulated by OSA in a concentration-dependent manner, with low concentrations (0.06-0.25mg/ml) having no deleterious effects on MIN6 cell viability, while higher concentrations (≥0.5mg/ml) caused increased Trypan blue uptake. OSA increased β-cell Ca2+ levels, an effect that was mediated by Ca2+ influx through voltage-operated calcium channels. OSA also reversibly stimulated insulin secretion from isolated human islets and its insulin secretagogue effects in MIN6 cells and human islets were partially dependent on the presence of extracellular Ca2+. These data indicate that low concentrations of the GS isolate OSA stimulate insulin secretion in vitro, at least in part as a consequence of Ca2+ influx, without compromising β-cell viability. Identification of the component of the OSA extract that stimulates regulated insulin exocytosis, and further investigation of its mode(s) of action, may provide promising lead targets for Type 2 diabetes therapy.
Diabetes mellitus is a complex metabolic disorder characterized by chronic hyperglycemia, and associated with long-term damage and dysfunction of various organs. Management of diabetes is therefore vital and involves maintaining euglycemia as much as possible by reducing blood glucose and by increasing insulin sensitivity and peripheral glucose uptake. Ayurveda has promoted the management of diabetes by regulating carbohydrate metabolism using several medicinal herbs, one of which is Gymnema sylvestre (GS). GS has been used in parts of India as a hypoglycemic agent and the results have been encouraging. Accordingly, we planned a quasi-experimental study to investigate the efficacy of the herb among type 2 diabetics. Patients enrolled from free-living population were purposively assigned to experimental or control groups, based on their willingness to participate in the study. The experimental group was supplemented with 500 mg of the herb per day for a period of 3 months, and the efficacy of the herb was assessed through a battery of clinical and biochemical tests. Supplementation of the diet with GS reduced polyphagia, fatigue, blood glucose (fasting and post-prandial), and glycated hemoglobin and there was a favorable shift in lipid profiles and in other clinico-biochemical tests. These findings suggest a beneficial effect of GS in the management of diabetes mellitus.
The effectiveness of GS4, an extract from the leaves of Gymnema sylvestre, in controlling hyperglycaemia was investigated in 22 Type 2 diabetic patients on conventional oral anti-hyperglycaemic agents. GS4 (400 mg/day) was administered for 18-20 months as a supplement to the conventional oral drugs. During GS4 supplementation, the patients showed a significant reduction in blood glucose, glycosylated haemoglobin and glycosylated plasma proteins, and conventional drug dosage could be decreased. Five of the 22 diabetic patients were able to discontinue their conventional drug and maintain their blood glucose homeostasis with GS4 alone. These data suggest that the beta cells may be regenerated/repaired in Type 2 diabetic patients on GS4 supplementation. This is supported by the appearance of raised insulin levels in the serum of patients after GS4 supplementation.
GS4, a water-soluble extract of the leaves of Gymnema sylvestre, was administered (400 mg/day) to 27 patients with insulin-dependent diabetes mellitus (IDDM) on insulin therapy. Insulin requirements came down together with fasting blood glucose and glycosylated haemoglobin (HbA1c) and glycosylated plasma protein levels. While serum lipids returned to near normal levels with GS4 therapy, glycosylated haemoglobin and glycosylated plasma protein levels remained higher than controls. IDDM patients on insulin therapy only showed no significant reduction in serum lipids, HbA1c or glycosylated plasma proteins when followed up after 10-12 months. GS4 therapy appears to enhance endogenous insulin, possibly by regeneration/revitalisation of the residual beta cells in insulin-dependent diabetes mellitus.
This paper examines eight published reviews each reporting results from several related trials. Each review pools the results from the relevant trials in order to evaluate the efficacy of a certain treatment for a specified medical condition. These reviews lack consistent assessment of homogeneity of treatment effect before pooling. We discuss a random effects approach to combining evidence from a series of experiments comparing two treatments. This approach incorporates the heterogeneity of effects in the analysis of the overall treatment efficacy. The model can be extended to include relevant covariates which would reduce the heterogeneity and allow for more specific therapeutic recommendations. We suggest a simple noniterative procedure for characterizing the distribution of treatment effects in a series of studies.
To estimate the impact of small reductions in the population distribution of diastolic blood pressure (DBP), such as those potentially achievable by population-wide lifestyle modification, on incidence of coronary heart disease (CHD) and stroke.
Published data from the Framingham Heart Study, a longitudinal cohort study, and from the National Health and Nutrition Examination Survey II, a national population survey, were used to examine the impact of a population-wide strategy aimed at reducing DBP by an average of 2 mm Hg in a population including normotensive subjects.
White men and women aged 35 to 64 years in the United States.
Incidence of CHD and stroke, including transient ischemic attacks (TIAs).
Data from overviews of observational studies and randomized trials suggest that a 2-mm Hg reduction in DBP would result in a 17% decrease in the prevalence of hypertension as well as a 6% reduction in the risk of CHD and a 15% reduction in risk of stroke and TIAs. From an application of these results to US white men and women aged 35 to 64 years, it is estimated that a successful population intervention alone could reduce CHD incidence more than could medical treatment for all those with a DBP of 95 mm Hg or higher. It could prevent 84% of the number prevented by medical treatment for all those with a DBP of 90 mm Hg or higher. For stroke (including TIAs), a population-wide 2-mm Hg reduction could prevent 93% of events prevented by medical treatment for those with a DBP of 95 mm Hg or higher and 69% of events for treatment for those with a DBP of 90 mm Hg or higher. A combination strategy of both a population reduction in DBP and targeted medical intervention is most effective and could double or triple the impact of medical treatment alone. Adding a population-based intervention to existing levels of hypertension treatment could prevent an estimated additional 67,000 CHD events (6%) and 34,000 stroke and TIA events (13%) annually among all those aged 35 to 64 years in the United States.
A small reduction of 2 mm Hg in DBP in the mean of the population distribution, in addition to medical treatment, could have a great public health impact on the number of CHD and stroke events prevented. Whether such DBP reductions can be achieved in the population through lifestyle interventions, in particular through sodium reduction, depends on the results of ongoing primary prevention trials as well as the cooperation of the food industry, government agencies, and health education professionals.