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ABSTRACT: AIMS: Controversies still exist regarding the relative contributions of insulin resistance and β-cell dysfunction to the pathogenesis of Type 2 diabetes in different populations. We examined the associations of baseline insulin resistance and β-cell function indices with the development of Type 2 diabetes in Koreans. METHODS: We analysed the clinical and laboratory data of 17 878 Korean adults (age 20-79 years) who underwent routine medical examinations with a median interval of 3.5 years (range 2.5-4.7 years). Using the homeostasis model assessment, insulin resistance (HOMA-IR) and β-cell function (HOMA-%B) indices at baseline were assessed. RESULTS: Those who developed diabetes (n = 732, 4.1%) had significantly higher fasting serum insulin level (53.4 ± 31.2 vs. 41.4 ± 23.4 pmol/l) and HOMA-IR (2.38 ± 1.45 vs. 1.65 ± 1.02) and lower HOMA-%B (74 ± 47 vs. 85 ± 48) at baseline (P < 0.001 for all). Both high HOMA-IR and low HOMA-%B were independently associated with an increased odds ratio of incident Type 2 diabetes. Among the participants who developed diabetes, 29% demonstrated predominant β-cell dysfunction (HOMA-%B < 25th percentile) and 51% had predominant insulin resistance (HOMA-IR > 75th percentile). When we divided the participants according to the median BMI of the whole population (23.7 kg/m(2) ), 49% of participants in the low BMI group demonstrated predominant β-cell dysfunction and 26% had predominant insulin resistance, whilst 21% in the high BMI group demonstrated mainly β-cell dysfunction and 60% had mainly insulin resistance. CONCLUSIONS: In individuals with low BMI, β-cell dysfunction is the predominant defect, whereas insulin resistance is the predominant pathogenetic factor in individuals with high BMI in the development of Type 2 diabetes in Koreans.
Diabetic Medicine 03/2013; · 2.90 Impact Factor
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ABSTRACT: Aims The optimal anthropometric measure of obesity or body fat distribution that best predicts the risk of Type 2 diabetes in Asians is unclear. Moreover, it has not been determined whether BMI modifies the effect of body fat distribution on diabetes risk in Asians. Methods We analysed the anthropometric and laboratory data of 7658 non-diabetic Korean adults (5061 men and 2597 women, aged 20-79 years) who underwent routine medical check-ups at 5-year intervals. BMI, waist circumference, waist-to-height ratio, and bioelectrical impedance (to calculate fat mass and per cent body fat) were measured at baseline. Results Of the 7658 participants, 278 subjects (3.6%) developed diabetes over 5 years. Each of the anthropometric measures of general obesity (BMI, fat mass, per cent body fat) and central body fat distribution (waist circumference and waist-to-height ratio) was a good predictor of Type 2 diabetes. However, when the areas under the receiver-operating characteristic curves were compared, BMI (0.697; 95% CI, 0.669-0.725), waist circumference (0.709, 0.682-0.736) and waist-to-height ratio (0.718, 0.692-0.743) were better predictors of diabetes risk than fat mass (0.672, 0.643-0.700) or per cent body fat (0.657, 0.628-0.686). In the low- (< 23 kg/m(2) ) and mid- (23-27 kg/m(2) ) BMI groups, the addition of waist-to-height ratio or waist circumference to BMI could improve the prediction of diabetes risk. Conclusions BMI, waist circumference and waist-to-height ratio were good predictors of Type 2 diabetes risk in Koreans. In non-obese or less obese subjects, measures of central body fat distribution can help improve the prediction of Type 2 diabetes risk when added to measures of general obesity.
Diabetic Medicine 03/2012; 29(11):1395-8. · 2.90 Impact Factor
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ABSTRACT: To investigate associations of obstructive and restrictive patterns of ventilatory dysfunction with insulin resistance and type 2 diabetes mellitus (DM) in Koreans.
We cross-sectionally examined clinical, laboratory, and pulmonary function data on 35,456 Korean adults (age 18-93 years, 40% women) recorded during regular health check-ups. Insulin resistance (IR) was determined from fasting serum insulin concentration and homeostasis model assessment (HOMA).
Individuals with type 2 DM and those with pre-diabetes (impaired fasting glucose levels) showed a higher prevalence of both restrictive (18% and 11%, respectively, VS. 8%; P<0.01) and obstructive (4.3% and 3.2%, respectively, VS. 2.3%; P<0.01) ventilatory dysfunction than did individuals with normal fasting glucose levels. Compared to subjects with normal ventilatory function, those with restrictive or obstructive ventilatory dysfunction were older, had higher systolic and diastolic blood pressure, and had elevated glucose and HbA1c levels. However, serum triglyceride, fasting insulin, and HOMA-IR were higher only in subjects with restrictive ventilatory dysfunction, and not in those with obstructive ventilatory dysfunction. On logistic regression analysis, the age and gender-adjusted odds ratio (OR) of restrictive ventilatory dysfunction for type 2 DM was 1.59 (95% confidence interval, 1.43-1.78). The increased OR remained significant after controlling for exercise, drinking, and smoking habits, presence of hypertension, body mass index, and waist circumference (OR=1.38 [1.23-1.55]). However, further adjustment for HOMA-IR attenuated the OR (1.11 [0.97-1.26]), making the OR statistically insignificant. In contrast, obstructive ventilatory dysfunction was not independently related to type 2 DM status.
Restrictive ventilatory dysfunction is independently associated with type 2 DM, probably VIA insulin resistance.
Experimental and Clinical Endocrinology & Diabetes 01/2011; 119(1):47-52. · 1.69 Impact Factor
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European Neuropsychopharmacology - EUR NEUROPSYCHOPHARMACOL. 01/2009; 19.
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ABSTRACT: To investigate whether fatty liver per se is an independent risk factor of incident type 2 diabetes mellitus (T2DM) in Koreans.
We examined the clinical and laboratory data of 5372 non-diabetic participants (3670 men and 1702 women; age 46.8 +/- 8.4 years, range 20-79 years) who underwent voluntary medical check-ups in 2000 and follow-up examinations in 2005.
Two hundred and thirty-three participants (4.3%) developed T2DM after 5 years. Univariate analysis showed that the development of diabetes was associated with: male sex; family history of diabetes; smoking; older age; higher body mass index (BMI), systolic and diastolic blood pressure, fasting plasma glucose (FPG), hepatic enzymes, total cholesterol and triglycerides; lower HDL cholesterol; and the presence of fatty liver on ultrasonography at baseline. In multiple logistic regression models, after adjusting for age, sex and alcohol consumption, patients with fatty liver were at significantly higher risk of developing T2DM compared to those without fatty liver [relative risk (RR) 3.92, 95% confidence interval (CI) 2.89-5.31]. After further adjustment for smoking, BMI, triglycerides, HDL cholesterol, FPG, alanine aminotransferase and ultrasonographer, fatty liver remained significantly associated with the development of T2DM (RR 1.51, 95% CI 1.04-2.20). Patients with moderate to severe fatty liver had higher risk ratios than patients with mild fatty liver. Exclusion of frequent drinkers did not attenuate the association.
Fatty liver on ultrasonography is associated with the development of T2DM, independently of classical risk factors, in Korean adults.
Diabetic Medicine 05/2008; 25(4):476-81. · 2.90 Impact Factor
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ABSTRACT: The alanine to threonine substitution at codon 54 (Ala54Thr) of the fatty acid binding protein 2 (FABP2) gene has been reported to be associated with increased fat oxidation and insulin resistance in several populations. It has been hypothesized that Ala54Thr substitution results in enhanced intestinal uptake of fatty acids and thereby an impairment of insulin action, but this hypothesis has not been proven in vivo. We studied the association between the Ala54Thr polymorphism of the FABP2 gene and intestinal (3)H-oleic acid absorption, as well as basal insulin level, basal metabolic rate, and fat oxidation rate in 96 healthy young Korean men. Among our subjects, the allele frequency of the Ala54Thr substitution was 0.34. Subjects with Thr54-encoding allele were found to have a higher mean fasting plasma insulin concentration and a higher basal fat oxidation rate compared with the subjects who were homozygous for the Ala54-encoding allele. However, there was no significant difference in basal metabolic rate or (3)H-oleic acid absorption according to the FABP2 gene polymorphism. These results suggest that the Ala54Thr substitution in the FABP2 gene is associated with increased fat oxidation and hyperinsulinemia in normal Korean men, but these effects are not mediated by an increase in the intestinal fatty acid absorption.
Metabolism 05/2001; 50(4):473-6. · 2.66 Impact Factor
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ABSTRACT: To investigate whether microalbuminuria is associated with the insulin resistance syndrome independent of hypertension and type 2 diabetes, we studied the association between microalbuminuria and features of insulin resistance syndrome in Korean general population. We selected 1006 subjects by a random cluster sampling among residents aged >40 years living in the Chung-Up district, a rural area of South Korea. Subjects were stratified by oral glucose tolerance status [normal glucose tolerance (NGT), impaired glucose tolerance (IGT), and diabetes mellitus], and by the presence or absence of hypertension. Urinary albumin excretion rate (UAER) was determined using timed overnight urine collection. Various cardiovascular risk factors including anthropometric indices, serum lipid, true insulin and proinsulin concentrations were also measured. The prevalence of microalbuminuria (UAER between 20 and 200 microg/min) increased as the glucose tolerance worsened (6.0% in NGT, 11.8% in IGT, and 21.8% in diabetes; chi(2) trend=25.9, P<0.001). Subjects with microalbuminuria had a higher body mass index (BMI), waist-to-hip circumference ratio (WHR), systolic and diastolic blood pressure (BP), fasting and 2 h plasma glucose, fasting plasma insulin and proinsulin levels, and lower HDL-cholesterol level than subjects without microalbuminuria. In multiple regression analysis, BMI, diastolic BP, 2 h plasma glucose, and fasting plasma insulin levels were found to be independent factors associated with UAER. Multiple logistic regression analysis showed that not only diabetes mellitus and hypertension, but also fasting hyperinsulinemia and waist-to-hip ratio were independent factors associated with the presence of microalbuminuria. When the normotensive, non-diabetic subjects were analyzed separately, fasting hyperinsulinemia and impaired glucose tolerance remained independent variables associated with the presence of microalbuminuria. These results show that microalbuminuria in the Korean general population is associated with hyperinsulinemia and central obesity, and suggest that microalbuminuria is a feature of the insulin resistance syndrome independent of hypertension or type 2 diabetes.
Diabetes Research and Clinical Practice 05/2001; 52(2):145-52. · 2.75 Impact Factor
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ABSTRACT: We examined the effects of high-fat diet (HFD) and exercise training on insulin-stimulated whole body glucose fluxes and several key steps of glucose metabolism in skeletal muscle. Rats were maintained for 3 wk on either low-fat (LFD) or high-fat diet with or without exercise training (swimming for 3 h per day). After the 3-wk diet/exercise treatments, animals underwent hyperinsulinemic euglycemic clamp experiments for measurements of insulin-stimulated whole body glucose fluxes. In addition, muscle samples were taken at the end of the clamps for measurements of glucose 6-phosphate (G-6-P) and GLUT-4 protein contents, hexokinase, and glycogen synthase (GS) activities. Insulin-stimulated glucose uptake was decreased by HFD and increased by exercise training (P < 0.01 for both). The opposite effects of HFD and exercise training on insulin-stimulated glucose uptake were associated with similar increases in muscle G-6-P levels (P < 0.05 for both). However, the increase in G-6-P level was accompanied by decreased GS activity without changes in GLUT-4 protein content and hexokinase activities in the HFD group. In contrast, the increase in G-6-P level in the exercise-trained group was accompanied by increased GLUT-4 protein content and hexokinase II (cytosolic) and GS activities. These results suggest that HFD and exercise training affect insulin sensitivity by acting predominantly on different steps of intracellular glucose metabolism. High-fat feeding appears to induce insulin resistance by affecting predominantly steps distal to G-6-P (e.g., glycolysis and glycogen synthesis). Exercise training affected multiple steps of glucose metabolism both proximal and distal to G-6-P. However, increased muscle G-6-P levels in the face of increased glucose metabolic fluxes suggest that the effect of exercise training is quantitatively more prominent on the steps proximal to G-6-P (i.e., glucose transport and phosphorylation).
AJP Endocrinology and Metabolism 06/2000; 278(6):E977-84. · 4.75 Impact Factor
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ABSTRACT: Previous studies have demonstrated that endogenous insulin secretion is not suppressed by exogenous insulin in patients with insulinoma. In this study we examined whether insulin secretion in insulinoma patients is suppressed by exogenous insulin during hypoglycaemia.
Sixteen insulinoma patients (5 men and 11 women) and 10 normal subjects were studied. Hyperinsulinaemic glucose clamp studies were performed at both euglycaemia (4.5 mmol/l glucose) and hypoglycaemia (2.5 mmol/l glucose).
In normal subjects, plasma C-peptide levels were suppressed by 66% during the euglycaemic hyperinsulinaemic clamps (P < 0.01). In contrast, in insulinoma patients, plasma C-peptide levels increased by 25% during the clamps (P < 0.05). In the hypoglycaemic hyperinsulinaemic clamps, plasma C-peptide levels were nearly completely (91%) suppressed in normal subjects and partially (39%) suppressed in patients with insulinoma (P < 0.01). The decrease in C-peptide levels during the hypoglycaemic clamps was > 30% in 12 (75%) of 16 insulinoma patients and > 50% in 8 (50%) patients.
This study demonstrated that in patients with insulinoma, insulin secretion was not suppressed by exogenous insulin during euglycaemia but was suppressed during hypoglycaemia, although the degree of suppression was less than that in normal subjects. Our results suggest that the feedback regulation of insulin secretion by exogenous insulin is partially retained in patients with insulinoma.
Clinical Endocrinology 02/2000; 52(1):87-92. · 3.17 Impact Factor
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ABSTRACT: Thiazide diuretics have been shown to decrease bone loss and improve bone mineral density, while long-term furosemide therapy has been suggested to decrease bone mineral content. However, the direct effects of these diuretics on osteoblastic cells are not well established. Some investigators have reported direct effects of thiazides on osteoblastic cells but the results remain controversial, and there are few data about the direct effect of furosemide on osteoblastic cells. We investigated the effects of hydrochlorothiazide (HCTZ) and furosemide on proliferation, alkaline phosphatase activity, osteocalcin, and interleukin-6/interleukin-11 (IL-6/IL-11) secretion in cultured normal human bone marrow stromal osteoprogenitor cells (hBMSCs). Treatment with HCTZ or furosemide for 24 hours in the concentration range of 10(-6) to 10(-4) mol/L did not affect 3H-thymidine incorporation in hBMSCs. Cellular alkaline phosphatase activity and osteocalcin production were not changed significantly by treatment with HCTZ or furosemide (up to 10(-4) mol/L) during culture. There was also no significant difference in IL-6 and IL-11 production in hBMSCs. These results suggested that HCTZ or furosemide had no significant direct effect on proliferation, alkaline phosphatase activity, osteocalcin, and IL-6/IL-11 production in hBMSCs, and the effects of these diuretics on bone mass may be related to the indirect action on calcium balance.
Metabolism 02/2000; 49(1):17-21. · 2.66 Impact Factor
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ABSTRACT: Quantitative ultrasound (QUS) of bone is a new radiation-free, low-cost method that measures both bone mass and bone quality. This study was performed to establish the normative data of QUS for Korean women and to determine the prevalence and risk factors of low quantitative ultrasound values in a Korean elderly population. We studied 238 healthy women aged 20-29 years working at a hospital, and 552 women over 50 years of age living in six villages of Chung-Up district, a rural area of South Korea, using QUS measurement of bone. Broadband ultrasound attenuation and speed of sound were measured at the calcaneus, and an index combining these factors (stiffness index) was calculated. T-score was calculated from the data of young normal subjects. Of the 552 elderly women, 34.2% had T-scores between -1.0 and -2.5, and 11.8% had T-scores below -2.5. The prevalence of low quantitative ultrasound values increased with older age, longer duration following menopause, lower body mass index, younger age at menopause and smoking. In multiple logistic regression analysis, age (odds ratio = 1.40 per 5 years, P < 0.05), duration following menopause (odds ratio = 1.35 per 5 years, P < 0.05) and body mass index (odds ratio = 0.78 per quartile, P < 0.05) were independently associated with low quantitative ultrasound values. These results suggested that quantitative ultrasound measurement of the calcaneus could be a useful tool for epidemiological surveys of bone mass.
Ultrasound in Medicine & Biology 01/2000; 26(1):35-40. · 2.29 Impact Factor
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ABSTRACT: It is well documented that glucocorticoid excess causes bone loss, but the mechanisms of these effects remain poorly defined. To understand further the mechanisms of glucocorticoid-induced osteoporosis, we investigated the effects of glucocorticoids on bone formation and bone resorption by examining the proliferation, functional activities, and cytokine secretion of cultured human bone marrow stromal cells (hBMSC). Treatment with dexamethasone for 24 h at the concentration of 10(-8) M significantly suppressed [(3)H]thymidine incorporation and further inhibition was observed with longer treatment (8 days) or higher concentration (10(-7) M). Alkaline phosphatase activity of hBMSC was markedly stimulated with addition of dexamethasone (10(-8) M), to 191 +/- 22% (after 4 days) and 317 +/- 46% (after 7 days) of control. Dexamethasone (10(-8) M) treatment for 48 h decreased the incorporation of [(3)H]proline into collagenase-digestible protein (CDP; 43.7+/-7.9% of control) and non-collagen protein (65.2+/-8.4% of control), with a greater effect on CDP. Northern blot analysis indicated that alpha1(I)-collagen mRNA level was decreased by dexamethasone to 27.6 +/- 9.0% of the control value after 1 day of exposure, and to 55.2 +/- 6.2% after 7 days. Dexamethasone markedly suppressed basal production of interleukin (IL)-6 and IL-11 and that stimulated by parathyroid hormone (PTH), IL-1alpha, or tumour necrosis factor-alpha in a dose-dependent manner. These results suggest that the glucocorticoid-induced bone loss is derived at least in part via inhibition of bone formation, which includes the suppression of osteoblast proliferation and collagen synthesis. As both basal and PTH-stimulated production of IL-6 and IL-11 are decreased by dexamethasone, the increased bone resorption observed in glucocorticoid-induced osteopenia does not appear to be mediated by IL-6 or IL-11.
Journal of Endocrinology 10/1999; 162(3):371-9. · 3.55 Impact Factor
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ABSTRACT: To examine whether reduced insulin secretory capacity or increased insulin secretory demand is associated with elevated ratio of plasma proinsulin to immunoreactive insulin (PI/IRI ratio) in non-diabetic subjects.
We measured various indices of insulin secretory function and insulin sensitivity by frequently sampled intravenous glucose tolerance test (FSIGT) and hyerglycemic glucose clamp in 21 healthy young men. We then examined the relationships between these indices and PI, IRI, or PI/IRI ratio in the fasting state.
Insulin sensitivity index (SI) measured by FSIGT correlated inversely with basal IRI (r=-0.53, P < 0.01) and PI levels (r=-0.57, P < 0.01), but there was no significant correlation between SI and PI/IRI ratio (r=0.26, NS). On the other hand, PI/IRI ratio correlated inversely with insulin secretory indices, such as acute insulin responses during FSIGT (r =-0.46, P < 0.01) and hyperglycemic glucose clamp (r=-0.54, P < 0.01) and submaximum insulin response during hyperglycemic glucose clamp (r=-0.59, P < 0.01).
These results indicate that elevated PI/IRI ratio may serve as a marker of reduced insulin secretory function in non-diabetic subjects.
Hormone and Metabolic Research 04/1999; 31(4):267-70. · 2.19 Impact Factor
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ABSTRACT: It is well known that excessive thyroid hormone in the body is associated with bone loss. However, the mechanism by which thyroid hormone affects bone turnover remains unclear. It has been shown that it stimulates osteoclastic bone resorption indirectly via unknown mediators secreted by osteoblasts. To determine if interleukin-6 (IL-6) or interleukin-11 (IL-11) could be the mediator(s) of thyroid hormone-induced bone loss, we studied the effects of 3,5,3'-tri-iodothyronine (T3) on basal and interleukin-1 (IL-1)-stimulated IL-6/IL-11 production in primary cultured human bone marrow stromal cells. T3 at 10(-12)-10(-8) M concentration significantly increased basal IL-6 production in a dose-dependent manner. It also had an additive effect on IL-1-stimulated IL-6 production, but failed to elicit a detectable effect on basal or IL-1-stimulated IL-11 production. Treatment with 17beta-estradiol (10(-8) M) did not affect the action of T3 on IL-6/IL-11 production. These results suggest that thyroid hormone may stimulate bone resorption by increasing basal and IL-1-induced IL-6 production from osteoblast-lineage cells, and these effects are independent of estrogen status.
Journal of Endocrinology 02/1999; 160(1):97-102. · 3.55 Impact Factor
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ABSTRACT: To examine the possible association between serum lipoprotein(a) [Lp(a)] concentration and proliferative diabetic retinopathy (PDR) in Korean patients with type 2 diabetes.
A total of 412 Korean outpatients with type 2 diabetes were examined. Diabetic retinopathy was determined by an ophthalmologist using fundoscopic examination. Serum Lp(a) levels were measured by two-site sandwich enzyme-linked immunosorbent assay.
The patients with PDR had higher serum Lp(a) levels than those with no diabetic retinopathy or with nonproliferative diabetic retinopathy (NPDR). Multiple logistic regression analysis showed that high serum Lp(a) levels and the presence of diabetic nephropathy were independent variables having a statistically significant association with PDR.
Korean type 2 diabetic patients with PDR had higher serum Lp(a) levels versus those with no diabetic retinopathy or with NPDR. Although these results suggest that Lp(a) might play a role in the occlusion of retinal capillaries leading to PDR, further prospective studies are required to prove the causal relationship.
Diabetes Care 01/1999; 21(12):2149-51. · 8.09 Impact Factor
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ABSTRACT: To examine effects of free fatty acids (FFA) on insulin-stimulated glucose fluxes, euglycemic hyperinsulinemic (86 pmol . kg-1 . min-1) clamps were performed for 5 h in conscious rats with (n = 8) or without (n = 8) lipid-heparin infusion. Glucose infusion rate required to maintain euglycemia was not different between the two groups during the first 2 h of clamps but became significantly lower with lipid-heparin infusion in the 3rd h and thereafter. To investigate changes in intracellular glucose metabolism during lipid-heparin infusion, additional clamps (n = 8 each) were performed for 1, 2, 3, or 5 h with an infusion of [3-3H]glucose. Insulin-stimulated whole body glucose utilization (Rd), glycolysis, and glycogen synthesis were estimated on the basis of tracer concentrations in plasma during the final 40 min of each clamp. Similar to changes in glucose infusion rate, Rd was not different between the two groups in the 1st and 2nd h but was significantly lower with lipid-heparin infusion in the 3rd h and thereafter. Whole body glycolysis was significantly lower with lipid-heparin infusion in all time periods, i.e., 1st, 2nd, 3rd, and 5th h of clamps. In contrast, whole body glycogen synthesis was higher with lipid-heparin infusion in the 1st and 2nd h but lower in the 5th h. Similarly, accumulation of [3H]glycogen radioactivity in muscle glycogen was significantly higher with lipid-heparin during the 1st and 2nd h but lower during the 3rd and 5th h. Glucose 6-phosphate (G-6-P) concentrations in gastrocnemius muscles were significantly higher with lipid-heparin infusion throughout the clamps. Muscle glycogen synthase (GS) activity was not altered with lipid-heparin infusion at 1, 2, and 3 h but was significantly lower at 5 h. Thus increased availability of FFA significantly reduced whole body glycolysis, but compensatory increase in skeletal muscle glycogen synthesis in association with accumulation of G-6-P masked this effect, and Rd was not affected in the early phase (within 2 h) of lipid-heparin infusion. Rd was reduced in the later phase (>2 h) of lipid-heparin infusion, when glycogen synthesis was reduced in association with reduced skeletal muscle GS activity.
The American journal of physiology 08/1998; 275(2 Pt 1):E338-44.
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ABSTRACT: Sixteen Korean female laborers who had been exposed to a cleaning solvent composed mainly of 2-bromopropane developed primary ovarian failure. Histologic findings from these patients' ovaries were similar to those observed in ovarian failure caused by radiation or chemotherapy, i.e., reduced number and developmental arrest of primary follicles, interstitial fibrosis and hyalinization of blood vessels. We followed their clinical course for 2 years and found that two patients recovered normal ovarian function spontaneously: one became pregnant and delivered a normal full-term baby, and the other resumed regular menstrual periods with normal hormonal values. Our observations support the idea that the increasing prevalence of ovarian failure in recent years might be due to an increase in presently unidentified environmental toxic agents.
European Journal of Endocrinology 06/1998; 138(5):554-6. · 3.42 Impact Factor
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ABSTRACT: Microalbuminuria in non-diabetic subjects is reportedly associated with increased cardiovascular morbidity and mortality. The prevalence of microalbuminuria in non-diabetic subjects varies widely from 5-6% in the UK and USA to 30-55% in Finland, Mexico, or Australian Aborigines. We studied cross-sectionally 497 clinically healthy, non-diabetic subjects more than 40 years of age who were living in Seoul, Korea for the prevalence of microalbuminuria and various cardiovascular risk factors. Urinary albumin-to-creatinine ratio (UACR) was determined in morning spot urine samples. Subjects were divided into normoalbuminuria (UACR < 2 mg/mmol) and microalbuminuria (UACR > or = 2 mg/mmol) groups. A total of 61 (12.2%) out of 497 subjects were found to have microalbuminuria. Subjects with microalbuminuria had significantly higher values in age, body mass index (BMI), waist-to-hip ratio in women, systolic and diastolic blood pressure, prevalence of hypertension, plasma cholesterol and triglyceride, and fasting plasma insulin. When subjects with microalbuminuria were compared with age-, sex-, and BMI-matched controls without microalbuminuria, systolic and diastolic blood pressure, and fasting plasma insulin concentrations were higher in microalbuminuric subjects. Multiple logistic regression analysis showed that fasting plasma insulin level and systolic blood pressure were independently associated with microalbuminuria. These results indicate that the prevalence of microalbuminuria in Korean non-diabetic subjects is lower than that in Mexico and Finland, but similar to that in Caucasians from the UK and USA, or in Pima Indians. Also, microalbuminuria in Korean non-diabetic subjects is associated with atherosclerotic risk factors such as hyperinsulinemia and hypertension, suggesting that microalbuminuria in these subjects may be a feature of insulin resistance syndrome.
Diabetes Research and Clinical Practice 06/1998; 40(3):191-9. · 2.75 Impact Factor
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ABSTRACT: To determine the incidence and risk factors for the development and progression of diabetic retinopathy in Korean patients with NIDDM.
A total of 186 patients with NIDDM who did not have proliferative diabetic retinopathy (PDR) at baseline were prospectively studied for 5.3 +/- 1.0 years in an outpatient clinic of a university hospital. The incidence and progression of diabetic retinopathy was determined by annual funduscopic examination by an ophthalmologist.
Of the 130 patients who were free of diabetic retinopathy at baseline, 30 developed it, giving an incidence of 44.4/1,000 person-years. Age and known duration of diabetes, mean fasting plasma glucose, and HbA1 levels during the follow-up period were higher in the patients who developed diabetic retinopathy. Of the 56 patients who had nonproliferative diabetic retinopathy at baseline, 11 developed PDR, giving an incidence of 37.5/1,000 person-years. The patients who progressed to PDR during follow-up (progressors) had a higher change of BMI and urinary albumin excretion rate at baseline and a higher mean HbA1 during the follow-up period than the nonprogressors. Cox proportional hazards analysis revealed that mean HbA1 was the only independent risk factor for both the development and progression of diabetic retinopathy.
The incidence of PDR in Korean NIDDM patients is comparable to that reported in other populations. Poor glycemic control is the most important risk factor for both the development and progression of diabetic retinopathy in NIDDM patients.
Diabetes Care 01/1998; 21(1):134-8. · 8.09 Impact Factor
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ABSTRACT: Interleukin-6 (IL-6) produced by osteoblastic cells plays an important role in the regulation of bone remodeling, mainly by stimulating osteoclast action. Although the IL-6 receptor is also found in osteoblastic cells, whether IL-6 exerts autocrine effects on osteoblastic cells is a matter of debate. This led us to study the effects of IL-6 on proliferation, osteoblastic activity as well as mRNA expression of various osteoblastic proteins in human bone marrow stromal osteoprogenitor cells (hBMSC). IL-6 did not affect cell proliferation assessed by [3H]-thymidine incorporation and osteoblastic activity determined by alkaline phosphatase activity and 45Ca incorporation. The expression of mRNAs for alkaline phosphatase, alpha 1 (I)-collagen, osteopontin and decorin also did not change significantly by IL-6 treatment. These results show that IL-6 does not have a significant autocrine role in regard to proliferation and osteoblastic activity of hBMSC.
Endocrine Research 09/1997; 23(3):181-90. · 0.97 Impact Factor
