Archna Narang

Impact of body mass index on thyroid functions in Indian children

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.

Dyslipidemia in subclinical hypothyroidism in an Indian population.

OBJECTIVES In view of inconsistent reports on the prevalence of dyslipidemia in subclinical hypothyroidism (SCH), we studied lipid abnormalities in Indian subjects with SCH. DESIGN AND METHODS A cross sectional study of 5343 subjects divided in two groups, Group-1 (age≤18 years) and Group-2 (age>18 years) was undertaken. They were further subdivided on the basis of their thyroid functional status: Normal (Control); SCH with TSH≤10.0mIU/L (SCH-1); and SCH with TSH>10mIU/L (SCH-2). RESULTS Prevalence of SCH was 14.7%. The only lipid abnormality in children and adolescents was low HDL in subjects with TSH>10mIU/L compared with controls. Serum total cholesterol (TC), and LDL cholesterol (LDL) were significantly higher in adults with TSH>10mIU/L compared to controls. There were no significant changes in lipid parameters in subjects with SCH having TSH≤10.0mIU/L, compared to controls. Serum TSH was positively and FT3 and FT4 were negatively correlated with TC and LDL. CONCLUSIONS Atherogenic lipid abnormalities were observed in adult subjects with SCH-2 (TSH>10.0mIU/L), and not in subjects with SCH-1 who had TSH≤10.0mIU/L in Indian population.

Reference intervals of serum calcium, ionized calcium, phosphate and alkaline phosphatase in healthy Indian school children and adolescents.

OBJECTIVE To develop age- and sex-specific reference interval of serum total calcium, ionized calcium, inorganic phosphates and alkaline phosphatase in healthy Indian children in the age group of 6-17 years. DESIGN AND METHOD Subjects for this study were selected from the schools of Delhi. The final analysis included 3,327 children in the age group of 6-17 years (1707 boys; 1620 girls). RESULTS The mean, standard deviation, 5th, 25th, 50th, 75th, 90th, 95th and 97th centile values of biochemical parameters for boys and girls are presented. All these parameters were significantly higher in boys than girls except serum ionized calcium. Serum total calcium (r -0.1362, p<0.001), serum inorganic phosphate (r -0.45, p<0.001) and serum alkaline phosphatase (r -0.5587, p<0.001) have shown inverse relationship with age. CONCLUSIONS Reference interval of selected biochemical parameters for healthy Asian-Indian children in the age group of 6-17 years is presented.

The evolution of thyroid function with puberty

Objective  This study was planned to describe thyroid functional status in different stages of puberty.

Reference intervals of serum lipid profile in healthy Indian school children and adolescents

OBJECTIVE To develop age and sex specific reference intervals of serum lipid parameters in healthy Indian children in the age group of 6-17 years. PARTICIPANTS Study subjects were selected from the schools of Delhi. Children with BMI either in overweight or obese category were excluded to generate reference intervals. The final analysis included 3076 children with BMI in normal range for age. RESULTS The mean±SD, 3rd, 10th, 25th, 50th, 75th, 90th and 97th centile values of lipid parameters are presented. All these parameters were significantly higher in girls than in boys. About 89.2% subjects had total cholesterol in acceptable range while 9.1% had borderline elevated and 1.5% had elevated TC. Optimal serum triglyceride levels were seen in 45.1% subjects while optimal levels of HDL cholesterol were seen in 0.3% subjects only. CONCLUSIONS Reference intervals of serum lipid parameters for healthy Indian children (6-17 years) are presented.

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.

Thyroid status two decades after salt iodization: country-wide data in school children from India.

Objective  Country‐wide evaluation of thyroid disorders in school children following two decades of universal salt iodization (USI) has not been carried out till date. This study was planned with aim to assess thyroid status of school children two decades after the launch of USI programme.

Establishment of Age-Specified Bone Mineral Density Reference Range for Indian Females Using Dual-Energy X-Ray Absorptiometry

We undertook this study to establish age-specified bone mineral density (BMD) reference range for Indian females using dual-energy X-ray absorptiometry. BMD at multiple skeletal sites was measured in 2034 healthy women aged 18--85yr. The effect of anthropometry and biochemical parameters on BMD was determined. Peak BMD was observed between 30 and 35yr at the hip, lumbar spine, and radius. Significant positive correlation of height and weight with BMD was observed at 33% radius, femur neck, and lumbar spine, whereas significant negative correlation was seen between serum alkaline phosphatase (ALP) and serum parathyroid hormone levels with BMD at aforementioned sites. On multivariate regression analysis, age, weight, and serum ALP were the most consistent contributors to variance in the BMD. Compared with age-matched US females, BMD of lumbar spine was significantly lower for our subjects in all age groups. Prevalence of osteoporosis among women aged older than 50yr was significantly higher based on Caucasian T-scores as opposed to using peak BMD/standard deviation values from the population under review at lumbar spine but not at femoral neck.

Association of insulin-like growth factor-1 and IGF binding protein-3 with 25-hydroxy vitamin D in pre-pubertal and adolescent Indian girls

Abstract Background: There is a high prevalence of vitamin D deficiency (VDD) in India. Molecular mechanisms suggest a strong relationship between vitamin D and growth factors. However, there is a paucity of literature with regard to a relationship between insulin-like growth factor-1 (IGF-1), insulin-like growth factor binding protein-3 (IGFBP-3) and vitamin D particularly in subjects with VDD. The objective of the study was to assess the relationship between growth factors and serum vitamin D-parathormone (PTH) status in school girls and study the impact of vitamin D supplementation on growth factors in pre-pubertal girls with VDD. Methods: Our study subjects were apparently healthy school girls aged 6–18 years. The baseline height, weight, body mass index (BMI), pubertal status, serum 25-hydroxy vitamin D (25OHD), PTH, IGF-1 and IGFBP-3 were assessed in 847 girls aged 6–18 years and in 190 pre-pubertal girls with VDD following supplementation. Results: The mean age, BMI and serum 25OHD of girls were 11.5±3.2 years, 18.7±4.8 kg/m2 and 9.9±5.6 ng/mL, respectively. VDD was observed in 94.6% of girls. Unadjusted serum IGF-1 levels and IGF-1/IGFBP-3 molar ratio were significantly higher in girls with severe VDD as compared to girls with mild-to-moderate VDD. However, these differences disappeared when adjusted for age, height or sexual maturation. The serum IGF-1 and IGFBP-3 levels increased significantly post supplementation with vitamin D. Conclusions: There were no differences in serum IGF-1 levels and the IGF-1/IGFBP-3 molar ratio among VDD categories when adjusted for age, height and sexual maturation in girls. Vitamin D supplementation resulted in a significant increase in serum IGF-1 levels in VDD pre-pubertal girls.

Assessment of insulin like growth factor-1 and IGF binding protein-3 in healthy Indian girls from Delhi and their correlation with age, pubertal status, obesity and thyroid hormonal status

Abstract Background: Population specific data and influence of sub-clinical hypothyroidism on insulin like growth factor-1 (IGF-1) and its binding protein-3 (IGFBP-3) in Indian children is lacking. This study was undertaken to evaluate serum IGF-1 and IGFBP-3 and their correlation with age, gender, pubertal status and thyroid functions. Methods: A total of 840 apparently healthy school girls aged 6–18 years, were recruited for the study and underwent assessment of height, weight, body mass index, pubertal status and serum T3, T4, TSH, IGF-1, IGFBP-3 and IGF-1/IGFBP-3 molar ratio. Results: The mean serum levels of IGF-1, IGFBP-3 levels and IGF-1/IGFBP-3 molar ratio were 381.8±240.5 ng/mL, 4.19±2.08 μg/mL and 40.5±37.2%, respectively. The serum IGF-1 and IGF-1/IGFBP-3 molar ratio increased significantly (p<0.0001) at 11 years followed by a steady yet non-significant rise till 16 years of age. A similar pattern was observed for IGFBP-3 showing a steep rise at 12 years and peaking at 16 years. Likewise, serum levels of IGF-1 and molar ratio of IGF-1/IGFBP-3 increased significantly with pubertal maturation from stage 1 to 3 and were higher in overweight girls compared to normal weight and obese girls. The growth factors were no different in girls with or without subclinical hypothyroidism. Conclusions: There was no significant impact of age on IGF-1 and IGFBP-3 in pre-pubertal girls. A sudden marked increase at 11 years followed by a gradual rise in growth factors till 16 years is indicative of pubertal initiation and maturation. Subclinical hypothyroidism did not influence growth factors in girls.BACKGROUND Population specific data and influence of sub-clinical hypothyroidism on insulin like growth factor-1 (IGF-1) and its binding protein-3 (IGFBP-3) in Indian children is lacking. This study was undertaken to evaluate serum IGF-1 and IGFBP-3 and their correlation with age, gender, pubertal status and thyroid functions. METHODS A total of 840 apparently healthy school girls aged 6-18 years, were recruited for the study and underwent assessment of height, weight, body mass index, pubertal status and serum T3, T4, TSH, IGF-1, IGFBP-3 and IGF-1/IGFBP-3 molar ratio. RESULTS The mean serum levels of IGF-1, IGFBP-3 levels and IGF-1/IGFBP-3 molar ratio were 381.8±240.5 ng/mL, 4.19±2.08 μg/mL and 40.5±37.2%, respectively. The serum IGF-1 and IGF-1/IGFBP-3 molar ratio increased significantly (p<0.0001) at 11 years followed by a steady yet non-significant rise till 16 years of age. A similar pattern was observed for IGFBP-3 showing a steep rise at 12 years and peaking at 16 years. Likewise, serum levels of IGF-1 and molar ratio of IGF-1/IGFBP-3 increased significantly with pubertal maturation from stage 1 to 3 and were higher in overweight girls compared to normal weight and obese girls. The growth factors were no different in girls with or without subclinical hypothyroidism. CONCLUSIONS There was no significant impact of age on IGF-1 and IGFBP-3 in pre-pubertal girls. A sudden marked increase at 11 years followed by a gradual rise in growth factors till 16 years is indicative of pubertal initiation and maturation. Subclinical hypothyroidism did not influence growth factors in girls.