Higher glucose, insulin and insulin resistance (HOMA-IR) in childhood predict adverse cardiovascular risk in early adulthood: the Pune Children's Study.

AIMS/HYPOTHESIS: The Pune Children's Study aimed to test whether glucose and insulin measurements in childhood predict cardiovascular risk factors in young adulthood. METHODS: We followed up 357 participants (75% follow-up) at 21 years of age who had undergone detailed measurements at 8 years of age (glucose, insulin, HOMA-IR and other indices). Oral glucose tolerance, anthropometry, plasma lipids, BP, carotid intima-media thickness (IMT) and arterial pulse wave velocity (PWV) were measured at 21 years. RESULTS: Higher fasting glucose, insulin and HOMA-IR at 8 years predicted higher glucose, insulin, HOMA-IR, BP, lipids and IMT at 21 years. A 1 SD change in 8 year variables was associated with a 0.10-0.27 SD change at 21 years independently of obesity/adiposity at 8 years of age. A greater rise in glucose-insulin variables between 8 and 21 years was associated with higher cardiovascular risk factors, including PWV. Participants whose HOMA-IR measurement remained in the highest quartile (n = 31) had a more adverse cardiovascular risk profile compared with those whose HOMA-IR measurement remained in the lowest quartile (n = 28). CONCLUSIONS/INTERPRETATION: Prepubertal glucose-insulin metabolism is associated with adult cardiovascular risk and markers of atherosclerosis. Our results support interventions to improve glucose-insulin metabolism in childhood to reduce cardiovascular risk in later life.

Marked gender difference in plasma total homocysteine concentrations in indian adults with low vitamin B12.

CONTEXT: Plasma total homocysteine (tHcy) is higher in men than women. OBJECTIVE: To explore the gender differences in tHcy in relation to determinants of one-carbon metabolism in Indian people with low B12 and adequate folate. SETTING: The study took place in rural and urban areas of Pune, India. DESIGN AND PARTICIPANTS: Participants were 441 men from the cross-sectional Coronary Risk of Insulin Sensitivity in Indian Subjects study (CRISIS) and premenopausal wives of 146 men (median ages 38 and 34 years, respectively). MAIN OUTCOME MEASURES: Gender difference in fasting tHcy in relation to plasma albumin and creatinine concentrations, lifestyle factors, diet and lean mass, plasma B12 and red cell folate (RCF) was assessed. RESULTS: Prevalence of high tHcy (> 15 µmol/L, median 14.4 µM) was 40 %, low B12 (< 150 pmol/L, 114 pmol/L) 66 %, and low RCF (< 283 nmol/L, 525 nmol/L) 8 %. Men had higher (1.8x) plasma tHcy concentrations (16.2 µmol/L) than women (9.5 µmol/L). Only 50 % of the gender difference was explained by age, lean mass, B12, and RCF. The difference remained after controlling for other explanatory variables. Women with a tHcy of 9.3 µM had the same B12 concentration (129 pmol/L) as men with a tHcy of 15 µM; and for a tHcy of 10.0 µmol/L women had the same RCF concentration (533 nmol/L) as men with a tHcy of 15 µmol/L. CONCLUSIONS: Adult Indian women have markedly lower tHcy concentrations compared to men. This suggests a lower threshold for supplementation to improve reproductive and cardiovascular outcomes.

Evaluation of tracer labelled methionine load test in vitamin B-12 deficient adolescent women.

BACKGROUND: Methionine loading test (MLT) has been used primarily to identify defects in transsulfuration of homocysteine in cystathionine beta synthase deficiency. It may not be as useful to evaluate remethylation pathway, in vitamin B-12 and folate deficiencies. OBJECTIVE: We used tracer isotope labelled MLT to interrogate transsulfuration and remethylation independently in vitamin B-12 deficiency. DESIGN: We studied vitamin B-12 deficient women with a tracer labelled MLT before and eleven months after treatment with vitamin B-12. The fractional contribution of [13C]homocysteine to breath CO2 was used as a measure of transsulfuration, and difference in the intracellular enrichment of [13C]methionine and that of [C2H3]methionine as a measure of remethylation of homocysteine. Combined pre- and post-treatment results were analyzed to investigate the association between plasma vitamin B-12 concentrations and measures of homocysteine metabolism. RESULTS: The subjects were 17 years old, with a BMI of 19.4 kg/m2. Treatment with vitamin B-12, 2µg/day increased plasma B-12 from 93 (78.7, 106.2) [median (25th, 75th centiles)] to 161.5 (125.5, 226.2) pmol/L; 44% were below <150pmol/L after treatment. Fasting homocysteine concentration was significantly lower and that of cysteine higher in subjects with B-12 levels >150pmol/L. The tracer estimated transsulfuration of homocysteine was lower and remethylation higher with B-12 levels >150pmol/L when compared with those <150pmol/L. CONCLUSIONS: The tracer labelled MLT in combination with fasting parameters is a robust way to estimate parameters of methionine metabolism and can be used in the field where prime-constant rate infusion studies cannot be done efficiently.

The Pune Rural Intervention in Young Adolescents (PRIYA) study: design and methods of a randomised controlled trial.

BACKGROUND: The Pune Maternal Nutrition Study (PMNS) was established to prospectively study the relationship of maternal nutrition to fetal growth and later cardiometabolic risk in the offspring. High homocysteine and low vitamin B12 levels in pregnancy predicted lower birthweight and higher insulin resistance at 6 years in the offspring. B12 deficiency was widespread in this population, due to low dietary intake. We therefore commenced a community-based intervention study with the underlying hypothesis that vitamin B12 supplementation of adolescent members of the PMNS cohort will improve birth weight, B12 status, and reduce future diabetes risk, in their offspring. METHODS: The individually randomised controlled trial commenced in September 2012, with boys and girls randomized into 3 groups, to receive daily for at least 3 years or until the birth of their first child: 1) vitamin B12 2 µg; or 2) vitamin B12 2 µg plus multiple micronutrients (MMN) plus 20 g of milk powder or 3) placebo. Iron and folic acid is given to all participants. Compliance is assessed by monthly supplement counts. Adverse events are recorded using a standardised questionnaire. The primary outcome is cord blood B12 concentration; based on 180-200 pregnancies in the girls, the study has ~80% power to detect a 0.5 SD change in newborn B12, in the B12 supplementation groups compared with controls, at the 5% significance level. Primary analysis will be by intention to treat. DISCUSSION: Our study tests a primordial prevention strategy through an intergenerational intervention started pre-conceptionally in both boys and girls using physiological doses of micronutrients to improve immediate pregnancy-related and long-term cardio metabolic outcomes. The results will have significant public health implications in a setting with widespread B12 deficiency but relative folate sufficiency. The randomised controlled trial design allows us to be confident that our findings will be causally relevant. TRIAL REGISTRATION: ISRCTN 32921044, applied on 14/09/2012. CTRI 2012/12/003212, registered on 02/12/2012. Retrospectively registered.

Nonaqueous phase synthesis of copper nanoparticles.

Copper nanoparticles were synthesized in a nonaqueous solution of cetyltrimethylammonium bromide with isopropanol as a solvent. Cetyltrimethylammonium bromide in isopropanol is observed to play a role as a catalyst where isopropanol is the reducing agent. The surface plasmon band characteristic for Cu nanoparticles can be observed at approximately 560 nm in the UV-visible spectra at molar ratios for Cu2+: cetyltrimethylammonium bromide of 1:15 and 1:30. On the other hand, at molar ratios of 1:0.25 and 1:1 the presence of peak at approximately 310 nm can be attributed to oligomeric clusters of Cu0. Formation of Cu0 was further confirmed from the X-ray diffraction analysis. The diffractograms exhibited peaks at 2theta = approximately 41.6 degrees, approximately 51.6 degrees, and approximately 74.3 degrees, corresponding to Cu0. At lower concentration of cetyltrimethylammonium bromide (i.e., Cu2+: cetyltrimethylammonium bromide = 1:0.25) higher degree of size dispersity (particles between approximately 5-20 nm) can be noted from transmission electron micrograph. On the other hand, at the highest concentration of cetyltrimethylammonium bromide (i.e., Cu2+: cetyltrimethylammonium bromide = 1:30), formation of finer sized particles with a lower degree of size variation, approximately 2-10 nm, can be observed.

Maternal homocysteine in pregnancy and offspring birthweight: epidemiological associations and Mendelian randomization analysis.

BACKGROUND: Disturbed one-carbon (1-C) metabolism in the mother is associated with poor fetal growth but causality of this relationship has not been established. METHODS: We studied the association between maternal total homocysteine and offspring birthweight in the Pune Maternal Nutrition Study (PMNS, Pune, India) and Parthenon Cohort Study (Mysore, India). We tested for evidence of causality within a Mendelian randomization framework, using a methylenetetrahydrofolatereductase (MTHFR) gene variant rs1801133 (earlier known as 677C→T) by instrumental variable and triangulation analysis, separately and using meta-analysis. RESULTS: Median (IQR) homocysteine concentration and mean (SD) birthweight were 8.6 µmol/l (6.7,10.8) and 2642 g (379) in the PMNS and 6.0 µmol/l (5.1,7.1) and 2871 g (443) in the Parthenon study. Offspring birthweight was inversely related to maternal homocysteine concentration-PMNS: -22 g/SD [95% confidence interval (CI): (-50, 5), adjusted for gestational age and offspring gender]; Parthenon: -57 g (-92, -21); meta-analysis: -40 g (-62, -17)]. Maternal risk genotype at rs1801133 predicted higher homocysteine concentration [PMNS: 0.30 SD/allele (0.14, 0.46); Parthenon: 0.21 SD (0.02, 0.40); meta-analysis: 0.26 SD (0.14, 0.39)]; and lower birthweight [PMNS: -46 g (-102, 11, adjusted for gestational age, offspring gender and rs1801133 genotype); Parthenon: -78 g (-170, 15); meta-analysis: -61 g (-111, -10)]. Instrumental variable and triangulation analysis supported a causal association between maternal homocysteine concentration and offspring birthweight. CONCLUSIONS: Our findings suggest a causal role for maternal homocysteine (1-C metabolism) in fetal growth. Reducing maternal homocysteine concentrations may improve fetal growth.

Influence of maternal vitamin B12 and folate on growth and insulin resistance in the offspring.

The burden of chronic noncommunicable diseases (NCDs) such as diabetes, obesity and cardiovascular disease is shifting rapidly to low- and middle-income countries. It calls for a review of the classic 'dogma' of genetic predisposition, precipitated by adult lifestyle. The paradigm of early life origins of chronic disease has focused attention on maternal health and nutrition as major determinants of the health of the offspring. India has high burden of maternal ill health and also of diabetes and cardiovascular disease, offering unique opportunities to study the links between the two. Pune studies showed that the Indian babies were thin but fat (more adipose) compared to European babies, and that maternal micronutrient status during pregnancy was a determinant of offspring size and body composition. Two thirds of the mothers had low vitamin B12 concentrations, while folate deficiency was rare. Higher circulating concentrations of homocysteine predicted smaller baby size. Follow-up studies revealed that higher maternal folate in pregnancy predicted higher adiposity and insulin resistance in the child at 6 years of age, and that low maternal vitamin B12 exaggerated the risk of insulin resistance. Low maternal vitamin B12 status is also associated with increased risk of neural tube defects and poor offspring cognitive functions. Our results suggest an important role for maternal one-carbon metabolism in offspring growth and programming of NCD risk. These ideas are supported by animal studies. Improvement of adolescent nutrition could effect intergenerational prevention of chronic diseases.

Spuriously high prevalence of prediabetes diagnosed by HbA(1c) in young indians partly explained by hematological factors and iron deficiency anemia.

OBJECTIVE: To examine the influence of glycemic and nonglycemic parameters on HbA(1c) concentrations in young adults, the majority of whom had normal glucose tolerance. RESEARCH DESIGN AND METHODS: We compared the diagnosis of normal glucose tolerance, prediabetes, and diabetes between a standard oral glucose tolerance test (OGTT; World Health Organization 2006 criteria) and HbA(1c) concentrations (American Diabetes Association [ADA] 2009 criteria) in 116 young adults (average age 21.6 years) from the Pune Children's Study. We also studied the contribution of glycemic and nonglycemic determinants to HbA(1c) concentrations. RESULTS: The OGTT showed that 7.8% of participants were prediabetic and 2.6% were diabetic. By ADA HbA(1c) criteria, 23.3% were prediabetic and 2.6% were diabetic. The negative predictive value of HbA(1c) was 93% and the positive predictive value was 20% (only 20% had prediabetes or diabetes according to the OGTT; this figure was 7% in anemic participants). Of participants, 34% were anemic, 37% were iron deficient (ferritin <15 ng/mL), 40% were vitamin B(12) deficient (<150 pmol/L), and 22% were folate deficient (<7 nmol/L). On multiple linear regression analysis, HbA(1c) was predicted by higher 2-h glucose (R(2) = 25.6%) and lower hemoglobin (R(2) = 7.7%). When hematological parameters were replaced by ferritin, vitamin B(12), and folate, HbA(1c) was predicted by higher glycemia (R(2) = 25.6%) and lower ferritin (R(2) = 4.3%). CONCLUSIONS: The use of HbA(1c) to diagnose prediabetes and diabetes in iron-deficient populations may lead to a spuriously exaggerated prevalence. Further investigation is required before using HbA(1c) as a screening tool in nutritionally compromised populations.

Vitamin B12 and folic acid supplementation and plasma total homocysteine concentrations in pregnant Indian women with low B12 and high folate status.

Maternal vitamin B12 deficiency and hyperhomocysteinemia predict poor pregnancy outcome, foetal adiposity and insulin resistance. In India amongst practicing clinicians and policy makers there is little appreciation of widespread vitamin B12 deficiency. We investigated 163 (86 rural, 77 urban) pregnant women attending antenatal clinics in a rural health centre and a referral hospital in the city of Pune, at 17, 28, and 34 weeks gestation for vitamin supplements, and circulating concentrations of vitamin B12, folate, and total homocysteine. At enrolment 80% rural and 65% urban women had low vitamin B12 but only two rural women had low folate concentrations. During pregnancy 85% rural and 95% of urban women received folic acid; 12% rural and 84% urban women also received vitamin B12. In women receiving no supplementation (n=17) plasma vitamin B12 and folate did not change from 17 to 34 weeks gestation, but homocysteine increased (p<0.05). Homocysteine concentrations at 34 weeks gestation in women receiving only folic acid (n=71, mean 8.4 (95% CI 7.8, 9.1) micromol/L) were comparable to the unsupplemented group (9.7 (7.3, 12.7), p=0.15), but women who received a total dose of >1000 microg of vitamin B12 up to 34 weeks (n=42, all with folic acid) had lower concentrations (6.7 (6.0, 7.4), p<0.001). Increasing dose of vitamin B12 (rs=-0.31, p=0.006) but not folic acid (rs=-0.19, p=0.11) was associated with lower plasma total homocysteine concentration. In vitamin B12 insufficient, folate replete pregnant women, vitamin B12 supplementation is associated with a reduction of plasma total homocysteine concentration in late pregnancy.