Normative data of body fat mass and its distribution as assessed by DXA in Indian adult population.

Dual-energy X-ray absorptiometry (DXA) assessment of body fat mass is precise and highly correlated with under water weighing. In view of ethnic differences, we undertook this study to prepare normative data for body fat mass in apparently healthy adult Indians and correlate it with body mass index (BMI). This cross-sectional population-based study included 2347 subjects (male: 924; female: 1423) aged >20 yr who participated in a general health examination. They were evaluated for anthropometry and body fat mass by DXA. All subjects were categorized as overweight and obese based on standard BMI criteria. Mean age and BMI were 49.1 ± 18.2yr and 25.0 ± 4.7kg/m(2), respectively. Mean percent total and regional fat (trunk, arm, and leg) reached maximum in the age group of 30-40yr in males and 50-60yr in females. Females had significantly higher total and regional fat mass compared with males. Fat mass was positively correlated with age (r = 0.224; p < 0.00001) and BMI (r = 0.668; p < 0.00001). Prevalence of overweight and obesity was seen in 2119 (46.1%) and 536 (13.8%), respectively, according to World Health Organization definition and 64.0% and 31.1%, respectively, as per Indian guidelines. Percent total body fat mass (PTBFM) of 25% in males and 30% in females corresponds to BMI of 22.0kg/m(2) with sensitivity of >80% and specificity of >70% in receiver operating characteristic curve analysis. Body fat mass in Indians is higher than that in Western populations for a given age and BMI. PTBFM of 25% in males and 30% in females corresponds to BMI of 22kg/m(2) in Indians.

Impact of body mass index on thyroid functions in Indian children.

OBJECTIVE: There is controversy about the relation of thyroid functions and body mass index. The present study was aimed to assess the relationship between thyroid function and body mass index in Indian school children. DESIGN: Population survey. PATIENTS: Data were collected from 25 schools in 19 cities across five different geographical zones of India. Children, who consented, were evaluated for anthropometry and blood tests. Children were categorized as overweight and obese based on standard BMI criteria. MEASUREMENTS: Serum samples were analysed for free T3, free T4, TSH and anti-TPO antibodies. RESULTS: A total of 13,691 children in the age group of 5-18 years formed the study population. The mean age and mean BMI were 11·9 ± 3·0 years and 18·48 ± 3·89 kg/m² respectively. Among these, 2119 (15·5%) children were overweight and 536 (3·9%) were obese. Subclinical hypothyroidism was present in 943 (6·9%) children.FT3 and TSH levels increased and FT4 levels decreased with increasing BMI in euthyroid boys and girls. Prevalence of SCH was significantly higher in obese/overweight children (9·0%, vs 6·5%; P = 0·034) as compared with normal BMI children. CONCLUSIONS: Serum FT3 and TSH were positively while FT4 was negatively associated with BMI in apparently healthy euthyroid children.

Relationship of body fat and its distribution with bone mineral density in Indian population.

Obesity has been associated with increased bone mineral density (BMD). There is evidence of differential effect of regional fat on BMD. Hence, we undertook this study to evaluate the correlation between total body fat and its distribution with BMD in nonobese (mean body mass index: 25.0 ± 4.7 kg/m²) Indian adult volunteers. A total of 2347 participants (men: 39.4% and women: 60.6%) included in this cross-sectional study were divided according to sex and age. Fasting blood samples were drawn for biochemical parameters. Percent total body, truncal, and leg fat and BMD at lumbar spine, femur, and forearm were measured by dual-energy X-ray absorptiometry. The BMD at all sites (radius, femur, and spine) increased from lowest to highest quartiles of percent body fat. Percent truncal fat was positively correlated with BMD at all sites in both sexes, except for femoral neck in men, where it had negative correlation. Percent leg fat was positively related with BMD at all sites in premenopausal women, and spine and radius BMD in postmenopausal women. However, in men, it had negative correlation with femoral neck BMD. On multiple regression analysis, regional fat had positive association with BMD at all sites after adjusting for age, sex, lean mass index, 25-hydroxyvitamin D, and intact parathyroid hormone levels. Leg-to-total body fat ratio was negatively associated with BMD at all sites in men and pre- and postmenopausal women. Percent total body and regional fat have positive association with BMD at all sites in men and women.

Efficacy of vitamin D loading doses on serum 25-hydroxy vitamin D levels in school going adolescents: an open label non-randomized prospective trial.

AIM: Vitamin D deficiency (VDD) among adolescents is a major health problem in India. The aim of this study was to assess the efficacy of therapeutic/loading doses of vitamin D supplementation on serum 25-hydroxy vitamin D (25OHD) levels in vitamin D deficient adolescents. METHODS: A total of 482 out of the 511 subjects recruited for the study were divided into three groups, each group receiving 60,000 IU of vitamin D3 weekly for 4, 6 and 8 weeks followed by 600 IU daily for 12 weeks, respectively. Clinical evaluation was followed by estimation of biochemical markers and serum 25OHD levels. RESULTS: VDD was observed in 94.8% of adolescents. All three vitamin D loading doses were equally efficacious in achieving vitamin D sufficiency >75 nmol/L (>30 ng/mL) in more than 90% subjects in the three groups. Mean 25OHD levels in groups 2 and 3 following maintenance therapy were 67.5±16.5 nmol/L (27.0±6.6 ng/mL) and 70.0±21.8 nmol/L (28.0±8.7 ng/mL), respectively. CONCLUSION: Supplementing 60,000 IU of vitamin D3 per week for 4-8 weeks, followed by 600 IU daily through fortified milk, is an effective strategy for achieving vitamin D sufficiency in Indian adolescents.

Height Velocity in Apparently Healthy North Indian School Children.

OBJECTIVE: Linear growth is best estimated by serial anthropometric data or height velocity (HV). In the absence of recent data on growth velocity, we undertook to establish normative data in apparently healthy North Indian children. MATERIALS AND METHODS: Prospective longitudinal study in a representative sample of 7710 apparently healthy children, aged 3-17 years from different regions of Delhi. Height was measured at baseline and at 12 months while pubertal examination was performed at baseline in a subset of children. RESULTS: The data on HV and puberty were available in 5635 participants (73.08%; 2341 boys and 3294 girls) and 1553 participants (622 boys; and 931 girls), respectively. The mean peak height velocity (PHV) was 7.82 ± 2.60 cm in boys seen at 12-12.9 years and 6.63 ± 1.81 cm in girls at 10-10.9 years Although late maturing boys had a greater HV than early or normal maturers, it did not vary with the age of pubertal maturation in girls. HV correlated with parental height in prepubertal boys, girls, and pubertal boys (P < 0.01) while no correlation was seen in girls. CONCLUSIONS: The study presents normal height velocities in North Indian children. A secular trend was observed in achieving PHV in both boys and girls.

Pubertal Onset in Apparently Healthy Indian Boys and Impact of Obesity.

OBJECTIVE: Primary - to determine the age of pubertal onset in Indian boys. Secondary - (a) to assess the impact of obesity on pubertal timing, (b) to assess the relationship between gonadotropins and puberty. DESIGN: Cross-sectional. SETTING: General community-seven schools across New Delhi. PARTICIPANTS: Random sample of 1306 school boys, aged 6-17 years. MATERIALS AND METHODS: Anthropometric measurement for weight and height and pubertal staging was performed for all subjects. Body mass index (BMI) was calculated to define overweight/obesity. Serum luteinizing hormone (LH), follicle stimulating hormone, and serum testosterone were measured in every sixth subject. MAIN OUTCOME MEASURE: Age at pubertal onset-testicular volume ≥4 mL (gonadarche) and pubic hair Stage II. RESULTS: Median age of attaining gonadarche and pubarche was 10.41 years (95% confidence interval [CI]: 10.2-10.6 years) and 13.60 (95% CI: 13.3-14.0 years), respectively. No significant difference in the age of attainment of gonadarche was observed in boys with normal or raised BMI, though pubarche occurred 8 months earlier in the latter group. Serum gonadotropins and testosterone increased with increasing stages of puberty but were unaffected by BMI. Serum LH level of 1.02 mIU/mL and testosterone level of >0.14 ng/mL showed the best prediction for pubertal onset. CONCLUSION: The study establishes a secular trend of the age of onset of puberty in Indian boys. Pubarche occurred earlier in overweight/obese boys. The cutoff levels of serum LH and testosterone for prediction of pubertal onset have been established.

Age of Onset of Puberty in Apparently Healthy School Girls from Northern India.

OBJECTIVE: To determine the age of pubertal onset and menarche in school-going girls, and to assess the impact of obesity on pubertal timing. DESIGN: Cross-sectional. SETTING: Seven schools across Delhi, India. PARTICIPANTS: 2010 school girls, aged 6-17 years. METHODS: Anthropometric measurement and pubertal staging was performed for all subjects. Menarche was recorded by status quo method. Body mass index was used to define overweight/obesity. Serum gonadotropins and serum estradiol were measured in every sixth participant. MAIN OUTCOME MEASURES: Age at thelarche and menarche analyzed for entire cohort and stratified based on body mass index. RESULTS: Median (95% CI) ages of thelarche, pubarche and menarche were 10.8 (10.7-10.9) y, 11.0. y (10.8-11.2) y and 12.4 y (12.2-12.5) y. Overweight/obese girls showed six months earlier onset of thelarche and menarche than those with normal BMI (P<0.05). Serum gonadotropins did not vary significantly in overweight/obese subjects. CONCLUSION: The study provides the normative data for pubertal growth in Indian girls. Pubertal onset occurs earlier in overweight and obese girls.

Reference range of thyroid function (FT3, FT4 and TSH) among Indian adults.

OBJECTIVES: To generate thyroid hormone reference norms using electro-chemiluminescence technique. DESIGN AND METHODS: Cross sectional study on apparently normal 4349 Delhi adults (18-86 years). Predetermined exclusion criteria (goiter, hypoechogenicity or nodularity on ultrasound, elevated anti-thyroid peroxidase antibody, hypo or hyperthyroidism and family history of thyroid dysfunction) excluded 2433 subjects leaving 1916 (916 males and 1000 females) as the reference population. RESULTS: Mean age and BMI of the reference population were 41.2 ± 18.1 years and 24.5 ± 4.4 kg/m(2) respectively. Median urinary iodine excretion was 233.6 µg/L (79-458;3rd-97th centile). The population was categorized into various age groups (18-30, 31-40, 41-50, 51-60, 61-70 and ≥ 70 years). Overall FT3 and FT4 values in the reference population irrespective of age, ranged from 2.4-8.8 (mean 4.6 ± 0.9) pmol/L and 10.1-24.8 (mean 15.40 ± 2.0) pmol/L, respectively. Mean TSH value in the reference population was 2.2 ± 0.9 mIU/L which was significantly lower than that of total population (3.8 ± 6.1; p<0.001). CONCLUSION: FT3 values were observed to be significantly higher in men than women (p=0.001). The centiles (3rd, 5th, 10th, 25th, 50th, 75th, 90th, 95th and 97th) of FT3, FT4 and TSH were derived for reference purposes in Indian adults. This community based study in Indian adults has established mean reference intervals for FT3, FT4 and TSH for different age groups for both sexes separately using strict exclusion criteria. These can be used as reference norms for Indian adults.