Ratnesh Kanwar

Prevalence of vitamin D deficiency and its relationship with thyroid autoimmunity in Asian Indians: a community-based survey.

25-Hydroxy vitamin D (25(OH)D) deficiency is linked with predisposition to autoimmune type 1 diabetes and multiple sclerosis. Our objective was to assess the relationship between serum 25(OH)D levels and thyroid autoimmunity. Subjects included students, teachers and staff aged 16-60 years (total 642, 244 males, 398 females). Serum free thyroxine, thyroid-stimulating hormone (TSH), and thyroid peroxidase autoantibodies (TPOAb), intact parathyroid hormone and 25(OH)D were measured by electrochemiluminescence and RIA, respectively. Thyroid dysfunction was defined if (1) serum TSH > or = 5 microU/ml and TPOAb>34 IU/ml or (2) TSH > or = 10 microU/ml but normal TPOAb. The mean serum 25(OH)D of the study subjects was 17.5 (sd 10.2) nmol/l with 87 % having values < or = 25 nmol/l. TPOAb positivity was observed in 21 % of subjects. The relationship between 25(OH)D and TPOAb was assessed with and without controlling for age and showed significant inverse correlation (r - 0.08, P = 0.04) when adjusted for age. The prevalence of TPOAb and thyroid dysfunction were comparable between subjects stratified according to serum 25(OH)D into two groups either at cut-off of < or = 25 or >25 nmol/l or first and second tertiles. Serum 25(OH)D values show only weak inverse correlation with TPOAb titres. The presence of such weak association and narrow range of serum 25(OH)D did not allow us to interpret the present results in terms of quantitative cut-off values of serum 25(OH)D. Further studies in vitamin D-sufficient populations with wider range of serum 25(OH)D levels are required to substantiate the findings of the current study.

Vitamin D status in pregnant Indian women across trimesters and different seasons and its correlation with neonatal serum 25-hydroxyvitamin D levels

The present cross-sectional study was conducted to determine the vitamin D status of pregnant Indian women and their breast-fed infants. Subjects were recruited from the Department of Obstetrics, Armed Forces Clinic and Army Hospital (Research and Referral), Delhi. A total of 541 apparently healthy women with uncomplicated, single, intra-uterine gestation reporting in any trimester were consecutively recruited. Of these 541 women, 299 (first trimester, ninety-seven; second trimester, 125; third trimester, seventy-seven) were recruited in summer (April-October) and 242 (first trimester, fifty-nine, second trimester, ninety-three; third trimester, ninety) were recruited in winter (November-March) to study seasonal variations in vitamin D status. Clinical, dietary, biochemical and hormonal evaluations for the Ca-vitamin D-parathormone axis were performed. A subset of 342 mother-infant pairs was re-evaluated 6 weeks postpartum. Mean serum 25-hydroxyvitamin D (25(OH)D) of pregnant women was 23.2 (SD 12.2) nmol/l. Hypovitaminosis D (25(OH)D < 50 nmol/l) was observed in 96.3 % of the subjects. Serum 25(OH)D levels were significantly lower in winter in the second and third trimesters, while serum intact parathormone (iPTH) and alkaline phosphatase levels were significantly higher in winter in all three trimesters. A significant negative correlation was found between serum 25(OH)D and iPTH in mothers (r - 0.367, P = 0.0001) and infants (r - 0.56, P = 0.0001). A strong positive correlation was observed between 25(OH)D levels of mother-infant pairs (r 0.779, P = 0.0001). A high prevalence of hypovitaminosis D was observed in pregnancy, lactation and infancy with no significant inter-trimester differences in serum 25(OH)D levels.

Prevalence of risk factors for coronary artery disease in an urban Indian population

Objective The objective of this study was to assess the prevalence of risk factors for coronary artery disease (CAD) in government employees across India. Methods The study population consisted of government employees in different parts of India ({n=10 642 men and n=1966 women; age 20–60 years}) and comprised various ethnic groups living in different environmental conditions. Recruitment was carried out in 20 cities across 14 states, and in one union territory. All selected individuals were subjected to a detailed questionnaire, medical examinations and anthropometric measurements. Blood samples were collected for blood glucose and serum lipid profile estimation, and resting ECG was recorded. Results were analysed using appropriate statistical tools. Results The study revealed that 4.6% of the study population had a family history of premature CAD. The overall prevalence of diabetes was 16% (5.6% diagnosed during the study and the remaining 10.4% already on medication). Hypertension was present in 21% of subjects. The prevalence of dyslipidemia was significantly high, with 45.6% of study subjects having a high total cholesterol/high density lipoprotein ratio. Overall, 78.6% subjects had two or more risk factors for CAD. Conclusions The present study demonstrates a high prevalence of CAD risk factors in the Indian urban population. Therefore, there is an immediate need to initiate measures to raise awareness of these risk factors so that individuals at high risk for future CAD can be managed.

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.

Peak bone mineral density of physically active healthy Indian men with adequate nutrition and no known current constraints to bone mineralization

We undertook this study to characterize peak bone density and evaluate its determinants in a healthy cohort of young adult male paramilitary personnel. Bone mineral density (BMD) was measured by dual-energy X-ray absorptiometry in 473 healthy men aged 21-40 yr. The effect of anthropometry and biochemical parameters on BMD was determined. Mean BMD values of L1-L4, forearm, total hip, and femoral neck were 1.170+/-0.137, 0.755+/-0.089, 1.129+/-0.130, and 1.115+/-0.133 g/cm(2), respectively. BMD values for 31- to 40-yr age group were lower than those of 20- to 30-yr age group except for forearm, which was higher in the former. Significant positive correlation was observed between height, weight, and body mass index with BMD. On multivariate regression analysis, weight was the most consistent contributor to variance in the BMD. Compared with age-matched US males, BMD of total hip and femoral neck were higher for Indian paramilitary personnel by 3.58% and 4.2%, whereas lumbar spine BMD was lower by 4.1%. In conclusion, peak BMD in healthy Indian males was achieved by 30 yr of age at lumbar spine and hip, with weight being the most consistent contributor to variance in BMD. Peak BMD in this population was comparable to that reported in white US males.

Reference range of thyroid hormones in normal Indian school‐age children

Objective  There is an ongoing debate on narrowing the TSH reference range in adults. In view of the scarce data on normal values of thyroid function tests in children from India, we planned to establish a reference range for thyroid hormones in school‐age children.

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.

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.