Thyroid function and bone mineral density among Indian subjects

Background: Thyroid hormones affect bone remodeling in patients with thyroid disease by acting directly or indirectly on bone cells. In view of limited information on correlation of thyroid function with Bone Mineral Density (BMD) in euthyroid subjects, we undertook this study to evaluate the correlation between thyroid function with BMD in subjects with normal thyroid function and subclinical hypothyroidism. Material and Methods: A total of 1290 subjects included in this cross sectional study, were divided in Group-1 with normal thyroid function and Group-2 with subclinical hypothyroidism. Fasting blood samples were drawn for the estimation of serum 25(OH)D, intact parathyroid hormone, total and ionized calcium, inorganic phosphorus and alkaline phosphatase. BMD at lumbar spine, femur and forearm was measured. Results: BMD at all sites (radius, femur and spine) were comparable in both groups. There was no difference in BMD when subjects were divided in tertiles of TSH in either group. In group-1, FT4 and TSH were positively associated with BMD at 33% radius whereas FT3 was negatively associated with BMD at femoral neck in multiple regression analysis after adjustment for age, sex, BMI, 25(OH)D and PTH levels. In group-2, there was no association observed between TSH and BMD at any site. Amongst all study subjects FT4 and FT3 were positively correlated with BMD at lumbar spine and radius respectively among all subjects. Conclusion: TSH does not affect BMD in euthyroid subjects and subjects with subclinical hypothyroidism. Thyroid hormones appear to have more pronounced positive effect on cortical than trabecular bone in euthyroid subjects

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 18–85 yr. The effect of anthropometry and biochemical parameters on BMD was determined. Peak BMD was observed between 30 and 35 yr 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 50 yr 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

Reference range of thyroid hormones in healthy school-age children: country-wide data from India

Objective: This study was planned to obtain normative data of thyroid functions in school-age children from different regions of India. Design and Methods: Students from 36 schools involving 13 states across four geographical zones of India were evaluated for goiter. Subjects who consented, underwent evaluation for serum FT3, FT4, TSH, anti-TPO antibodies and thyroid ultrasound. From this, a “reference population” was obtained by excluding those with personal or family history of thyroid disease, use of thyroid medications, goiter, hypoechogenicity or nodularity on ultrasound or positive anti-thyroid antibodies. Results: Of 24,685 students clinically evaluated, 8665 formed part of the study. The reference population comprised 5343 subjects. The mean, median, 3rd and 97th percentiles of FT3, FT4 and TSH for each year (6–17 years) were obtained. Conclusions: This community based study in Indian school-age children provides reference intervals for thyroid hormones and evidence against narrowing the TSH reference range