Linear growth and fat and lean tissue gain during childhood: associations with cardiometabolic and cognitive outcomes in adolescent Indian children

Background: We aimed to determine how linear growth and fat and lean tissue gain during discrete age periods from birth to adolescence are related to adolescent cardiometabolic risk factors and cognitive ability.Methods: Adolescents born to mothers with normal glucose tolerance during pregnancy from an Indian birth cohort (N = 486, age 13.5 years) had detailed anthropometry and measurements of body fat (fat%), fasting plasma glucose, insulin and lipid concentrations, blood pressure and cognitive function. Insulin resistance (HOMA-IR) was calculated. These outcomes were examined in relation to birth measurements and statistically independent measures (conditional SD scores) representing linear growth, and fat and lean tissue gain during birth-1, 1–2, 2–5, 5–9.5 and 9.5–13.5 years in 414 of the children with measurements at all these ages.Results: Birth length and linear growth at all ages were positively associated with current height. Fat gain, particularly during 5–9.5 years was positively associated with fat% at 13.5 years (0.44 SD per SD [99.9% confidence interval: 0.29,0.58]). Greater fat gain during mid-late childhood was associated with higher systolic blood pressure (5–9.5 years: 0.23 SD per SD [0.07,0.40]) and HOMA-IR (5–9.5 years: 0.24 [0.08,0.40], 9.5–13.5 years: 0.22 [0.06,0.38]). Greater infant growth (up to age 2 years) in linear, fat or lean components was unrelated to cardiometabolic risk factors or cognitive function.Conclusion: This study suggests that factors that increase linear, fat and lean growth in infancy have no adverse cardiometabolic effects in this population. Factors that increase fat gain in mid-late childhood may increase cardiometabolic risk, without any benefit to cognitive abilities

Power Analysis in Health Policy and Systems Research: a Guide to Research Conceptualisation

Power is a growing area of study for researchers and practitioners working in the field of health policy and systems research (HPSR). Theoretical development and empirical research on power are crucial for providing deeper, more nuanced understandings of the mechanisms and structures leading to social inequities and health disparities; placing contemporary policy concerns in a wider historical, political and social context; and for contributing to the (re)design or reform of health systems to drive progress towards improved health outcomes. Nonetheless, explicit analyses of power in HPSR remain relatively infrequent, and there are no comprehensive resources that serve as theoretical and methodological starting points. This paper aims to fill this gap by providing a consolidated guide to researchers wishing to consider, design and conduct power analyses of health policies or systems. This practice article presents a synthesis of theoretical and conceptual understandings of power; describes methodologies and approaches for conducting power analyses; discusses how they might be appropriately combined; and throughout reflects on the importance of engaging with positionality through reflexive praxis. Expanding research on power in health policy and systems will generate key insights needed to address underlying drivers of health disparities and strengthen health systems for all

Cohort profile: Mysore Parthenon Birth Cohort

The Mysore Parthenon Birth Cohort was established to examine the long-term effects of maternal glucose tolerance and nutritional status on cardiovascular disease risk factors in the offspring. During 1997-98, 830 of 1233 women recruited from the antenatal clinics of the Holdsworth Memorial Hospital (HMH), Mysore, India, underwent an oral glucose tolerance test. Of these, 667 women delivered live babies at HMH. Four babies with major congenital anomalies were excluded, and the remaining 663 were included for further follow-up. The babies had detailed anthropometry at birth and at 6-12-monthly intervals subsequently. Detailed cardiovascular investigations were done at ages 5, 9.5 and 13.5 years in the children, and in the parents at the 5-year and 9.5-year follow-ups. This ongoing study provides extensive data on serial anthropometry and body composition, physiological and biochemical measures, dietary intake, nutritional status, physical activity measures, stress reactivity measures and cognitive function, and socio-demographic parameters for the offspring. Data on anthropometry, cardiovascular risk factors and nutritional status are available for mothers during pregnancy. Anthropometry and risk factor measures are available for both parents at follow-up

Accelerometers for measuring physical activity behavior in Indian children

Objective: To examine the validity of accelerometers forcharacterizing habitual physical activity patterns in Indianchildren.Design: Cohort study.Setting: Holdsworth Memorial Hospital, Mysore.Subjects: Children (N=103, mean age 6.6 years) selectedfrom an ongoing birth cohort study.Methods: Physical activity was measured over 7 daysusing accelerometers (MTI Actigraph) and concurrentparent-maintained activity diaries. Actigraph counts perminute representing sedentary (<10), light (<400),moderate (<3000) and vigorous (?3000) activity weredetermined using a structured activity session in aseparate group of 10 children. In 46 children chosen forvalidating accelerometers, time spent in different activitylevels according to diaries was determined. EnergyExpenditure (EE) was calculated from diaries using afactorial method.Results: Ninety-eight children wore the monitor for ?4days. Total counts and time spent in different activity levelswere similar in boys and girls (P>0.2). Among 46 childrenchosen for comparisons, time spent in sedentary (r =0.48,P=0.001), light (r=0.70, P<0.001) and moderate activities(r=0.29, P=0.054) according to diaries correlated withthose derived from counts, and total Actigraph countscorrelated with EE (r=0.42, P=0.004). Bland-Altmananalysis showed systematic bias, and wide limits ofagreement between these methods for time spent indifferent activity levels.Conclusions: Accelerometers are a well tolerated andobjective way of measuring activity behavior in free-livingchildren. Though accelerometer counts correlate with timespent in activity of varying intensity and energyexpenditure derived from parent-maintained diaries, widelimits of agreement show that the limitations ofaccelerometers need to be recognized in interpreting thedata that they generate

Distributions of water in pores of periodic mesoporous organosilicates – a proton solid state MAS NMR study

Solid state proton (1H) magic angle spinning (MAS) NMR has been employed to study the distribution of confined water in ethane substituted periodic mesoporous organosilicate (PMOE) materials. Proton spectra acquired at different hydration levels are analysed and interpreted in terms of water clusters of various sizes and distributions of water layers on the pore surface. For comparison, we also performed similar experiments on SBA-15. The formation of larger clusters at lower hydration suggests that the pores of PMOE are getting filled with water at lower hydration levels than those in SBA-15. For PMOE, the simultaneous presence of two major resonances in the ranges 3.6–4.1 ppm and 4.4–5.2 ppm and their behaviour upon hydration imply a water layer distribution that is the sum of two contributions, corresponding to fully filled and partially filled pores or pore segments. Furthermore, the behaviour mentioned above suggests that both radial and axial filling mechanisms play a significant role in the hydration process. For SBA-15, as a function of hydration, we observed a smooth variation in the proton chemical shift of the main dynamic resonance. In accordance with previous studies, this is attributed to the gradual increase in the average thickness of water layers with an increase in hydration, and to a pore filling mechanism that is predominantly radial

Glucose tolerance and insulin resistance in Indian children: relationship to infant feeding pattern

AIMS/HYPOTHESIS: Our objective was to examine whether longer duration of breast-feeding and later introduction of complementary foods are associated with lower glucose concentrations and insulin resistance (IR-HOMA) in Indian children. METHODS: Breast-feeding duration (6 categories from <3 to ≥18 months) and age at introduction of complementary foods (4 categories from <4 to ≥6 months) were recorded at 1, 2 and 3 year follow-up of 568 children from a birth cohort in Mysore, India. At 5- and 9.5-years of age 518 children were assessed for glucose tolerance and IR-HOMA. RESULTS: All the children were initially breast-fed; 90% were breast-fed for ≥6 months and 56.7% started complementary foods at or before the age of 4 months. Each category increase in breast-feeding duration was associated with lower fasting insulin concentration (β=−0.05 pmol/L (95% CI: −0.10, −0.004); P=0.03) and IR-HOMA (β=−0.05 (95% CI: −0.10, −0.001); P=0.046) at 5-years, adjusted for the child’s sex, age, current BMI, socio-economic status, parent’s education, rural/urban residence, birthweight and maternal gestational diabetes status. Longer duration of breastfeeding was associated with higher 120-minute glucose concentration at 5-years (β=0.08 mmol/L (95% CI: 0.001, 0.15; P=0.03) but lower 120-minute glucose concentration at 9.5-years (β=−0.09 (95% CI: −0.16, −0.03; P=0.006). Age at starting complementary foods was unrelated to the children’s glucose tolerance and IR-HOMA. CONCLUSIONS/INTERPRETATION: Within this cohort, in which prolonged breast-feeding was the norm, there was evidence of a protective effect of longer duration of breast-feeding against glucose intolerance at 9.5-years. At 5-years longer duration of breast-feeding was associated with lower IR-HOMA

Adiposity and cortisol response to stress in Indian adolescents

SETTING: Holdsworth Memorial Hospital, Mysore, India.OBJECTIVE: We examined associations of different adiposity measures with cortisol responses during the Trier Social Stress Test for children (TSST-C).DESIGN: Descriptive study.PARTICIPANTS: Adolescents aged 13.5y from a birth cohort were recruited (N=269, 133 boys).METHODS: The stressor (TSST-C) was 5-minutes each of public speaking and mental arithmetic tasks in front of two unfamiliar 'judges'. Salivary cortisol concentrations were measured at baseline and at regular intervals after TSST-C. Weight, height, sub scapular and triceps skinfold thickness, and waist and hip circumference were measured, and percentage body fat was estimated (fat%; bioimpedance). Body mass index (BMI) and Waist-to-hip ratio (WHR) were calculated. All variables were converted into within-cohort SD scores before analysis. Stress-induced change in cortisol concentrations from baseline (cortisol response) was examined in relation to adiposity.RESULTS: Stress increased cortisol concentrations significantly from baseline (mean (SD): 5.5 (6.4) ng/mL; P&lt;0.001). Higher WHR was associated with lower cortisol response at 20 and 30-minutes after stress (~0.13 SD decrease in cortisol response per SD higher WHR, P&lt;0.05). Higher fat% was also associated with lower cortisol response only in girls 20-minutes post-stress (0.23 SD lower response per SD higher fat%, P=0.004). Sum of skinfold thickness and BMI were not associated with cortisol responses.CONCLUSION: Abdominal adiposity is associated with reduced hypothalamic-pituitary-adrenal axis reactivity to stress in this adolescent population.</p

Gestational diabetes and the incidence of diabetes in the 5 years following the index pregnancy in South Indian women

This study was carried out to examine the incidence of diabetes and the factors associated with this in a cohort of South Indian women 5 years after they were examined for gestational diabetes (GDM). Women (N=630) whose GDM status was determined (Carpenter-Coustan criteria; GDM: N=41) delivered live babies without major anomalies at the Holdsworth Memorial Hospital, Mysore. Of these, 526 women (GDM: N=35) available for follow-up after 5 years underwent a 2-h oral glucose tolerance test and detailed anthropometry. Diabetes was determined using WHO criteria, and Metabolic Syndrome using IDF criteria recommended for south Asian women. The incidence of diabetes (37% versus 2%) and Metabolic Syndrome (60% versus 26%) was considerably higher in women with previous GDM compared to non-GDM women. GDM women who developed diabetes had lower gestational insulin area-under-the-curve (P=0.05). They had larger waist-to-hip ratio, skinfolds, body mass index, and lower 30-min insulin increment at follow-up than other GDM women. In all, history of diabetes in first-degree relatives was independently associated with higher incidence of diabetes (P&lt;0.001). Our findings suggest high diabetes and cardiovascular risks in women with previous GDM. Follow-up of these women after delivery would provide opportunities to modify adverse lifestyle factor

Breast feeding duration, age at starting periods and high BMI risk and adiposity in Indian children

This study utilized data from a prospective birth cohort study on 568 Indian children, to determine whether a longer duration of breastfeeding and later introduction of solid feeding were associated with a reduced higher body mass index (BMI) and less adiposity. Main outcomes were high BMI (&gt;90th within-cohort sex-specific BMI percentile) and sum of skinfold thickness (triceps and subscapular) at age 5. Main exposures were breastfeeding (six categories from 1–4 to ?21 months) and age of starting regular solid feeding (four categories from ?3 to ?6 months). Data on infant-feeding practices, socio-economic and maternal factors were collected by questionnaire. Birthweight, maternal and child anthropometry were measured. Multiple regression analysis that accounted for potential confounders demonstrated a small magnitude of effect for breastfeeding duration or introduction of solid feeds on the risk of high BMI but not for lower skinfold thickness. Breastfeeding duration was strongly negatively associated with weight gain (0–2 years) [adjusted ? = –0.12 standard deviation, 95% confidence interval (CI): –0.19 to –0.05 per category change in breastfeeding duration, P = 0.001], and weight gain (0–2 years) was strongly associated with high BMI at 5 years (adjusted odds ratio = 3.8, 95% CI: 2.53–5.56, P &lt; 0.001). In our sample, findings suggest that longer breastfeeding duration and later introduction of solids has a small reduction on later high BMI risk and a negligible effect on skinfold thickness. However, accounting for sampling variability, these findings cannot exclude the possibility of no effect at the population level

Mother's lifetime nutrition and the size, shape and efficiency of the placenta

BackgroundStudies have shown that the shape and size of the placenta at birth predict blood pressure in later life. The influences that determine placental morphology are largely unknown. We have examined the role of mother’s body size. MethodsWe studied 522 neonates who were born in a maternity hospital in Mysore, South India. The weight of the placenta and the length and breadth of its surface, were measured after delivery.ResultsHigher maternal fat mass predicted a larger placental surface (p=0.02), while larger maternal head circumference predicted a more oval placental surface (p=0.03). Higher maternal fat mass and larger maternal head circumference were associated with greater placental efficiency, indicated by lower ratios of the length (p=0.0003 and p=0.0001 respectively) and breadth (p=0.0002 and p&lt;0.0001) of the surface to birthweight. In a sub-sample of 51 mothers whose own birthweight was available, higher maternal birthweight was related to lower ratios of the length and breadth of the surface to birthweight (p=0.01 and 0.002). Maternal height was unrelated to placental size or shape.ConclusionsHigher maternal fat mass, reflecting the mother’s current nutritional state, and larger maternal head circumference, reflecting the mother’s fetal/infant growth, are associated with changes in the shape and size of the placental surface and greater placental efficiency. We suggest that these associations reflect effects of the mother’s nutrition at different stages of her lifecourse on the development of the placenta and on materno-placento-fetal transfer of nutrients