[Show abstract][Hide abstract] ABSTRACT: Background
Diabetes has been defined on the basis of different bio-markers, including fasting plasma glucose (FPG), 2-h plasma glucose in an oral glucose tolerance test (2hOGTT), and HbA1c. We assessed the effect of different diagnostic definitions on both the population prevalence of diabetes and the classification of previously undiagnosed individuals as having diabetes versus not having diabetes in a pooled analysis of data from population-based health examination surveys in different regions.
We used data from 96 population-based health examination surveys that had measured at least two of the bio-markers used for defining diabetes. Diabetes was defined using HbA1c (HbA1c ≥6·5% or history of diabetes diagnosis or using insulin or oral hypoglycemic drugs) compared with either FPG only or FPG-or-2hOGTT definitions (FPG ≥7·0 mmol/L or 2hOGTT ≥11·1 mmol/L or history of diabetes or using insulin or oral hypoglycemic drugs). We calculated diabetes prevalence, taking into account complex survey design and survey sample weights. We compared the prevalences of diabetes using different definitions graphically and by regression analyses. We calculated sensitivity and specificity of diabetes diagnosis based on HbA1c compared with diagnosis based on glucose among previously undiagnosed individuals (i.e., excluding those with history of diabetes or using insulin or oral hypoglycemic drugs). We calculated sensitivity and specificity in each survey, and then pooled results using a random-effects model. We assessed the sources of heterogeneity of sensitivity by meta-regressions for study characteristics selected a priori.
Population prevalence of diabetes based on FPG-or-2hOGTT was correlated with prevalence based on FPG alone (r=0·98), but was higher by 2–6 percentage points at different prevalence levels. Prevalence based on HbA1c was lower than prevalence based on FPG in 42·8% of age–sex–survey groups and higher in another 41·6%; in the other 15·6%, the two definitions provided similar prevalence estimates. The variation across studies in the relation between glucose-based and HbA1c-based prevalences was partly related to participants' age, followed by natural logarithm of per person gross domestic product, the year of survey, mean BMI, and whether the survey population was national, sub-national, or from specific communities. Diabetes defined as HbA1c 6·5% or more had a pooled sensitivity of 52·8% (95% CI 51·3–54·3%) and a pooled specificity of 99·74% (99·71–99·78%) compared with FPG 7·0 mmol/L or more for diagnosing previously undiagnosed participants; sensitivity compared with diabetes defined based on FPG-or-2hOGTT was 30·5% (28·7–32·3%). None of the preselected study-level characteristics explained the heterogeneity in the sensitivity of HbA1c versus FPG.
Different biomarkers and definitions for diabetes can provide different estimates of population prevalence of diabetes, and differentially identify people without previous diagnosis as having diabetes. Using an HbA1c-based definition alone in health surveys will not identify a substantial proportion of previously undiagnosed people who would be considered as having diabetes using a glucose-based test.
[Show abstract][Hide abstract] ABSTRACT: Child stunting (low height-for-age) is a marker of chronic undernutrition and predicts children's subsequent physical and cognitive development. Around one third of the world's stunted children live in India. Our study aims to assess the impact, cost-effectiveness, and scalability of a community intervention with a government-proposed community-based worker to improve growth in children under two in rural India.
The study is a cluster randomised controlled trial in two rural districts of Jharkhand and Odisha (eastern India). The intervention tested involves a community-based worker carrying out two activities: (a) one home visit to all pregnant women in the third trimester, followed by subsequent monthly home visits to all infants aged 0-24 months to support appropriate feeding, infection control, and care-giving; (b) a monthly women's group meeting using participatory learning and action to catalyse individual and community action for maternal and child health and nutrition. Both intervention and control clusters also receive an intervention to strengthen Village Health Sanitation and Nutrition Committees. The unit of randomisation is a purposively selected cluster of approximately 1000 population. A total of 120 geographical clusters covering an estimated population of 121,531 were randomised to two trial arms: 60 clusters in the intervention arm receive home visits, group meetings, and support to Village Health Sanitation and Nutrition Committees; 60 clusters in the control arm receive support to Committees only. The study participants are pregnant women identified in the third trimester of pregnancy and their children (n = 2520). Mothers and their children are followed up at seven time points: during pregnancy, within 72 hours of delivery, and at 3, 6, 9, 12 and 18 months after birth. The trial's primary outcome is children's mean length-for-age Z scores at 18 months. Secondary outcomes include wasting and underweight at all time points, birth weight, growth velocity, feeding, infection control, and care-giving practices. Additional qualitative and quantitative data are collected for process and economic evaluations.
This trial will contribute to evidence on effective strategies to improve children's growth in India.
ISRCTN register 51505201 ; Clinical Trials Registry of India number 2014/06/004664.
BMC Public Health 04/2015; 15(1):384. DOI:10.1186/s12889-015-1655-z · 2.26 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: BACKGROUND:
High blood pressure, blood glucose, serum cholesterol, and BMI are risk factors for cardiovascular diseases and some of these factors also increase the risk of chronic kidney disease and diabetes. We estimated mortality from cardiovascular diseases, chronic kidney disease, and diabetes that was attributable to these four cardiometabolic risk factors for all countries and regions from 1980 to 2010.
We used data for exposure to risk factors by country, age group, and sex from pooled analyses of population-based health surveys. We obtained relative risks for the effects of risk factors on cause-specific mortality from meta-analyses of large prospective studies. We calculated the population attributable fractions for each risk factor alone, and for the combination of all risk factors, accounting for multicausality and for mediation of the effects of BMI by the other three risks. We calculated attributable deaths by multiplying the cause-specific population attributable fractions by the number of disease-specific deaths. We obtained cause-specific mortality from the Global Burden of Diseases, Injuries, and Risk Factors 2010 Study. We propagated the uncertainties of all the inputs to the final estimates.
In 2010, high blood pressure was the leading risk factor for deaths due to cardiovascular diseases, chronic kidney disease, and diabetes in every region, causing more than 40% of worldwide deaths from these diseases; high BMI and glucose were each responsible for about 15% of deaths, and high cholesterol for more than 10%. After accounting for multicausality, 63% (10·8 million deaths, 95% CI 10·1-11·5) of deaths from these diseases in 2010 were attributable to the combined effect of these four metabolic risk factors, compared with 67% (7·1 million deaths, 6·6-7·6) in 1980. The mortality burden of high BMI and glucose nearly doubled from 1980 to 2010. At the country level, age-standardised death rates from these diseases attributable to the combined effects of these four risk factors surpassed 925 deaths per 100 000 for men in Belarus, Kazakhstan, and Mongolia, but were less than 130 deaths per 100 000 for women and less than 200 for men in some high-income countries including Australia, Canada, France, Japan, the Netherlands, Singapore, South Korea, and Spain.
The salient features of the cardiometabolic disease and risk factor epidemic at the beginning of the 21st century are high blood pressure and an increasing effect of obesity and diabetes. The mortality burden of cardiometabolic risk factors has shifted from high-income to low-income and middle-income countries. Lowering cardiometabolic risks through dietary, behavioural, and pharmacological interventions should be a part of the global response to non-communicable diseases.
[Show abstract][Hide abstract] ABSTRACT: Growth failure remains a persistent challenge in many countries, and understanding child growth patterns is critical to the development of appropriate interventions and their evaluation. The interpretation of changes in mean height-for-age z scores (HAZs) over time to define catch-up growth has been a subject of debate. Most studies of child growth have been cross-sectional or have focused on children through age 5 y.OBJECTIVE: The aim was to characterize patterns of linear growth among individuals followed from birth into adulthood.DESIGN: We compared HAZs and difference in height (cm) from the WHO reference median at birth, 12 mo, 24 mo, mid-childhood, and adulthood for 5287 individuals from birth cohorts in Brazil, Guatemala, India, the Philippines, and South Africa.RESULTS: Mean HAZs were <0 at birth in the 3 cohorts with data and ranged from -0.6 (Brazil) to -2.9 (Guatemala) at age 24 mo. Between 24 mo and mid-childhood, HAZ values increased by 0.3-0.5 in South Africa, Guatemala, and the Philippines and were unchanged in Brazil and India. Between mid-childhood and adulthood, mean HAZs increased in all cohorts but remained <0 in adulthood [mean range: -0.3 (Brazil) to -1.8 (Guatemala and Philippines)]. However, from 24 mo to adulthood, height differences from the reference median became greater.CONCLUSIONS: From age 2 y to adulthood, mean HAZs increased, even though height deficits relative to the reference median also increased. These 2 metrics may result in different interpretations of the potential for and the impact of catch-up growth in height.
American Journal of Clinical Nutrition 07/2014; 100(3). DOI:10.3945/ajcn.114.084368 · 6.77 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: OBJECTIVE: The prevalence of Bitot's spots (BS) is often used to quantify vitamin A deficiency burden in India, both before and after mega-dose vitamin A supplementation (MVAS) programmes. However, the proportion of BS cured following this intervention is unclear in contemporary times. The current study evaluated the responsiveness of BS over 1 year to MVAS administered as per the national programme in rural India. DESIGN: Prospective, community-based, 1-year follow-up of a cohort. SETTING: Rural Uttar Pradesh, India. SUBJECTS: Two hundred and sixty-two children with BS, aged between 1 and 5 years, administered 60 mg (retinol equivalent) of vitamin A on diagnosis and after 1 month. Cure or resolution was defined if there was no discernible BS in either eye. RESULTS: During 1 year, only three children were lost to follow-up. At 6 months of follow-up (MVAS at baseline and 1 month later), 51·1 (95% CI 45·3, 57·3) % were classified as cured. The corresponding figure at 1 year (additional MVAS at 6 months) was 59·9 (95% CI 54·1, 65·9) %. Among those cured at 6 months, about half and three-quarters had resolved at 2 and 3 months, respectively. Apart from male gender, there were no significant sociodemographic or clinical predictors of response. CONCLUSIONS: Substantial non-response to MVAS at 6 months (49%) and 1 year (40%) of follow-up suggests that presently in the Indian subcontinent, BS is a relatively crude indicator of severe current vitamin A deficiency. For programmatic decisions and evaluation, the public health burden of vitamin A deficiency should not be assessed solely through BS.
Public Health Nutrition 06/2013; 17(7):1-6. DOI:10.1017/S1368980013001584 · 2.68 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: BACKGROUND: Fast weight gain and linear growth in children in low-income and middle-income countries are associated with enhanced survival and improved cognitive development, but might increase risk of obesity and related adult cardiometabolic diseases. We investigated how linear growth and relative weight gain during infancy and childhood are related to health and human capital outcomes in young adults. METHODS: We used data from five prospective birth cohort studies from Brazil, Guatemala, India, the Philippines, and South Africa. We investigated body-mass index, systolic and diastolic blood pressure, plasma glucose concentration, height, years of attained schooling, and related categorical indicators of adverse outcomes in young adults. With linear and logistic regression models, we assessed how these outcomes relate to birthweight and to statistically independent measures representing linear growth and weight gain independent of linear growth (relative weight gain) in three age periods: 0-2 years, 2 years to mid-childhood, and mid-childhood to adulthood. FINDINGS: We obtained data for 8362 participants who had at least one adult outcome of interest. A higher birthweight was consistently associated with an adult body-mass index of greater than 25 kg/m(2) (odds ratio 1·28, 95% CI 1·21-1·35) and a reduced likelihood of short adult stature (0·49, 0·44-0·54) and of not completing secondary school (0·82, 0·78-0·87). Faster linear growth was strongly associated with a reduced risk of short adult stature (age 2 years: 0·23, 0·20-0·52; mid-childhood: 0·39, 0·36-0·43) and of not completing secondary school (age 2 years: 0·74, 0·67-0·78; mid-childhood: 0·87, 0·83-0·92), but did raise the likelihood of overweight (age 2 years: 1·24, 1·17-1·31; mid-childhood: 1·12, 1·06-1·18) and elevated blood pressure (age 2 years: 1·12, 1·06-1·19; mid-childhood: 1·07, 1·01-1·13). Faster relative weight gain was associated with an increased risk of adult overweight (age 2 years: 1·51, 1·43-1·60; mid-childhood: 1·76, 1·69-1·91) and elevated blood pressure (age 2 years: 1·07, 1·01-1·13; mid-childhood: 1·22, 1·15-1·30). Linear growth and relative weight gain were not associated with dysglycaemia, but a higher birthweight was associated with decreased risk of the disorder (0·89, 0·81-0·98). INTERPRETATION: Interventions in countries of low and middle income to increase birthweight and linear growth during the first 2 years of life are likely to result in substantial gains in height and schooling and give some protection from adult chronic disease risk factors, with few adverse trade-offs. FUNDING: Wellcome Trust and Bill & Melinda Gates Foundation.
The Lancet 03/2013; 382(9891). DOI:10.1016/S0140-6736(13)60103-8 · 45.22 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Objective:
To examine associations between maternal height and child growth during 4 developmental periods: intrauterine, birth to age 2 years, age 2 years to mid-childhood (MC), and MC to adulthood.
Pooled analysis of maternal height and offspring growth using 7630 mother-child pairs from 5 birth cohorts (Brazil, Guatemala, India, the Philippines, and South Africa). We used conditional height measures that control for collinearity in height across periods. We estimated associations between maternal height and offspring growth using multivariate regression models adjusted for household income, child sex, birth order, and study site.
Maternal height was associated with birth weight and with both height and conditional height at each age examined. The strongest associations with conditional heights were for adulthood and 2 years of age. A 1-cm increase in maternal height predicted a 0.024 (95% CI: 0.021-0.028) SD increase in offspring birth weight, a 0.037 (95% CI: 0.033-0.040) SD increase in conditional height at 2 years, a 0.025 (95% CI: 0.021-0.029 SD increase in conditional height in MC, and a 0.044 (95% CI: 0.040-0.048) SD increase in conditional height in adulthood. Short mothers (<150.1 cm) were more likely to have a child who was stunted at 2 years (prevalence ratio = 3.20 (95% CI: 2.80-3.60) and as an adult (prevalence ratio = 4.74, (95% CI: 4.13-5.44). There was no evidence of heterogeneity by site or sex.
Maternal height influences offspring linear growth over the growing period. These influences likely include genetic and non-genetic factors, including nutrition-related intergenerational influences on growth that prevent the attainment of genetic height potential in low- and middle-income countries.
The Journal of pediatrics 03/2013; 163(2). DOI:10.1016/j.jpeds.2013.02.002 · 3.79 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Zinc deficiency is a significant public health problem in low- and middle-income countries. Zinc is essential for the formation and migration of neurons, along with the formation of neuronal interconnections called synapses. Its deficiency could interfere with the formation of neural pathways and neurotransmission, thus affecting behavior and development. Zinc supplementation provided to infants and children is a possible strategy to improve the mental and motor development of infants and children at high risk of zinc deficiency. The review authors searched the medical literature for studies that evaluated mental and motor development in infants and children randomly assigned to receive either zinc supplements or a 'placebo' (fake) supplement. We found 13 relevant studies. Eight studies measured development using the Mental Development Index and the Psychomotor Development Index of the Bayley Scales of Infant Development. We found no difference between the results for those who had taken zinc supplements and those who had taken a placebo. Two studies measured children's attainment of motor milestones. Again, no difference as found whether zinc supplements were taken or not. No study measured possible side effects of zinc supplementation such as vomiting, diarrhea or anemia. Overall, the results of the studies provided no convincing evidence that zinc supplements had any beneficial effect on mental and motor development in infants and children.
[Show abstract][Hide abstract] ABSTRACT: Overweight and obesity prevalence are commonly used for public and policy communication of the extent of the obesity epidemic, yet comparable estimates of trends in overweight and obesity prevalence by country are not available.
We estimated trends between 1980 and 2008 in overweight and obesity prevalence and their uncertainty for adults 20 years of age and older in 199 countries and territories. Data were from a previous study, which used a Bayesian hierarchical model to estimate mean body mass index (BMI) based on published and unpublished health examination surveys and epidemiologic studies. Here, we used the estimated mean BMIs in a regression model to predict overweight and obesity prevalence by age, country, year, and sex. The uncertainty of the estimates included both those of the Bayesian hierarchical model and the uncertainty due to cross-walking from mean BMI to overweight and obesity prevalence.
The global age-standardized prevalence of obesity nearly doubled from 6.4% (95% uncertainty interval 5.7-7.2%) in 1980 to 12.0% (11.5-12.5%) in 2008. Half of this rise occurred in the 20 years between 1980 and 2000, and half occurred in the 8 years between 2000 and 2008. The age-standardized prevalence of overweight increased from 24.6% (22.7-26.7%) to 34.4% (33.2-35.5%) during the same 28-year period. In 2008, female obesity prevalence ranged from 1.4% (0.7-2.2%) in Bangladesh and 1.5% (0.9-2.4%) in Madagascar to 70.4% (61.9-78.9%) in Tonga and 74.8% (66.7-82.1%) in Nauru. Male obesity was below 1% in Bangladesh, Democratic Republic of the Congo, and Ethiopia, and was highest in Cook Islands (60.1%, 52.6-67.6%) and Nauru (67.9%, 60.5-75.0%).
Globally, the prevalence of overweight and obesity has increased since 1980, and the increase has accelerated. Although obesity increased in most countries, levels and trends varied substantially. These data on trends in overweight and obesity may be used to set targets for obesity prevalence as requested at the United Nations high-level meeting on Prevention and Control of NCDs.
Population Health Metrics 11/2012; 10(1):22. DOI:10.1186/1478-7954-10-22 · 2.11 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The utility of iron fortification of food to improve iron deficiency, anemia, and biological outcomes is not proven unequivocally.
The objectives were to evaluate 1) the effect of iron fortification on hemoglobin and serum ferritin and the prevalence of iron deficiency and anemia, 2) the possible predictors of a positive hemoglobin response, 3) the effect of iron fortification on zinc and iron status, and 4) the effect of iron-fortified foods on mental and motor development, anthropometric measures, and infections.
Randomized and pseudorandomized controlled trials that included food fortification or biofortification with iron were included.
Data from 60 trials showed that iron fortification of foods resulted in a significant increase in hemoglobin (0.42 g/dL; 95% CI: 0.28, 0.56; P < 0.001) and serum ferritin (1.36 μg/L; 95% CI: 1.23, 1.52; P < 0.001), a reduced risk of anemia (RR: 0.59; 95% CI: 0.48, 0.71; P < 0.001) and iron deficiency (RR: 0.48; 95% CI: 0.38, 0.62; P < 0.001), improvement in other indicators of iron nutriture, and no effect on serum zinc concentrations, infections, physical growth, and mental and motor development. Significant heterogeneity was observed for most of the evaluated outcomes. Sensitivity analyses and meta-regression for hemoglobin suggested a higher response with lower trial quality (suboptimal allocation concealment and blinding), use of condiments, and sodium iron edetate and a lower response when adults were included.
Consumption of iron-fortified foods results in an improvement in hemoglobin, serum ferritin, and iron nutriture and a reduced risk of remaining anemic and iron deficient.
American Journal of Clinical Nutrition 07/2012; 96(2):309-24. DOI:10.3945/ajcn.111.031500 · 6.77 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: BACKGROUND: Carotid intima-media thickness (CIMT) and carotid plaques represent preclinical markers of atherosclerosis. We sought to describe predictors of CIMT and carotid plaques, including early life growth, in a young urban Indian cohort free of clinical cardiovascular disease (CVD). METHODS: In 2006-2009, we performed B-mode carotid ultrasound on 600 participants (mean [SD] age 36 [1.1] years; 45% women) from the New Delhi Birth Cohort to evaluate CIMT and carotid plaques (>1mm). Height and weight were recorded at birth, 2 and 11years of age. Data on CVD risk factors, anthropometry, medical history, socio-economic position, and lifestyle habits were collected in 1998-2002. RESULTS: Mean (SD) CIMT for men and women was 0.91 (0.12) and 0.86 (0.13) mm, respectively. Carotid plaque was present in 33% of men and 26% of women. Waist circumference in 1998-2002 was positively associated with CIMT (β coefficient 0.26mm [0.17, 0.36] per SD) and carotid plaque (OR 1.27 [1.06,1.52] per SD) in 2006-2009. Higher triglycerides, PAI-1, insulin resistance, and diastolic blood pressure, metabolic syndrome, and lower HDL-cholesterol and physical activity predicted higher CIMT and/or plaque (p<0.05). Longer length at 2years was associated with higher CIMT (p<0.05). These associations were attenuated after adjusting for adult waist circumference. CONCLUSIONS: These are the first prospective data from India showing that early life growth, adult socio-demographics, and CVD risk factors predict future CIMT and/or carotid plaque. These relationships appear primarily mediated through central adiposity, highlighting the importance of maintaining a healthy weight in early adulthood to prevent CVD.
International journal of cardiology 04/2012; 167(4). DOI:10.1016/j.ijcard.2012.03.180 · 4.04 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Background Middle ear infections are common, especially among young children, usually causing earache and some temporary (occasionally permanent) hearing loss. Zinc is an essential micronutrient, which has a role in the optimal functioning of the immune system and resistance to infection. It must be consumed regularly as it cannot be stored in the body. Some people, especially children in low- and middle-income countries, may not have adequate zinc intake from food alone. Researchers have examined the potential role of zinc supplements in preventing infective illnesses. Therefore we wanted to discover whether zinc supplements have any role in preventing middle ear infections. Study characteristics The review authors searched the medical literature for studies up to March 2014. We searched for trials which compared middle ear infections in people randomly selected to receive zinc supplements or who did not receive supplements. We found 10 eligible studies, all conducted amongst young children. The total number of participants was 6820. Nine trials were conducted in low- and middle-income countries. Seven trials were conducted on healthy children. Participants included both males and females. Results The results of the trials provided no convincing evidence that zinc supplements reduce the occurrence of middle ear infections in healthy children. However, in one small study of severely malnourished children, those receiving zinc supplements had fewer middle ear infections. The only adverse effect was vomiting. Quality of evidence The trial evidence included is generally of good quality, with a low risk of bias. All the included trials included otitis media only as a secondary outcome. Therefore, there was a potential to miss trials which were less publicised or less well indexed within the electronic databases.
[Show abstract][Hide abstract] ABSTRACT: To evaluate the associations between birth weight (BW), infancy, and childhood weight gain and adult body composition.
Subjects included participants of five birth cohort studies from low and middle income nations (Brazil, Guatemala, India, Philippines, and South Africa; n = 3432). We modeled adult body composition as a function of BW and conditional weight gain (CW), representing changes in weight trajectory relative to peers, in three age intervals (0-12 months, 12-24 months, 24 months-mid childhood).
In 34 of 36 site- and sex-specific models, regression coefficients associated with BW and CWs were higher for adult fat-free than for fat mass. The strength of coefficients predicting fat-free mass relative to those predicting fat mass was greatest for BW, intermediate for CWs through 24 months, and weaker thereafter. However, because fat masses were smaller and showed larger variances than fat-free masses, weaker relationships with fat mass still yielded modest but significant increases in adult % body fat (PBF). CW at 12 months and mid-childhood tended to be the strongest predictors of PBF, whereas BW was generally the weakest predictor of PBF. For most early growth measures, a 1 SD change predicted less than a 1% change in adult body fat, suggesting that any health impacts of early growth on changes in adult body composition are likely to be small in these cohorts.
BW and weight trajectories up to 24 months tend to be more strongly associated with adult fat-free mass than with fat mass, while weight trajectories in mid-childhood predict both fat mass and fat-free mass.
American Journal of Human Biology 01/2012; 24(1):5-13. DOI:10.1002/ajhb.21227 · 1.70 Impact Factor