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 ≥ 5 μ U/ml and TPOAb>34 IU/ml or (2) TSH ≥ 10 μ U/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 ≤ 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 ≤ 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

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

Glutamic acid decarboxylase (anti-GAD) & tissue transglutaminase (anti-TTG) antibodies in patients with thyroid autoimmunity

Background & objectives: Several autoimmune disorders have been reported to be associated with autoimmune thyroiditis and may coexist with other organ-specific autoantibodies. The aim of the present study was to evaluate the presence of tissue transglutaminase (anti-TTG) and glutamic acid decarboxylase (anti-GAD) antibodies in patients suffering from autoimmune thyroiditis as diagnosed by anti-thyroid peroxidase (anti-TPO) antibodies, which may indicate high risk for developing celiac disease or type 1 diabetes mellitus. Methods: Five thousand children and 2800 adults were screening as part of a general health examination done on a voluntary basis in four different parts of Delhi. A total of 577 subjects positive for anti-TPO antibody constituted the cases. Equal number of age and sex matched anti-TPO antibody negative controls were randomly selected from the same cohort to form paired case control study. The cases and controls were further divided into two groups as follows: group-1 (children and adolescent 18 yr). Serum samples of cases and controls were analysed for thyroid function test (FT3, FT4, and TSH), anti-TTG and anti-GAD antibodies. Results: A total of 1154 subjects (577 cases and 577 controls) were included in this study. Hypothyroidism was present in 40.2 per cent (232) cases compared to only 4.7 per cent (27) in controls (P<0.001). Anti-TTG and anti-GAD antibodies were present in 6.9 and 12.5 per cent subjects among cases compared to 3.5 per cent (P=0.015) and 4.3 per cent (P=0.001) in controls, respectively. Only anti-GAD antibody were significantly positive in cases among children and adolescents (P =0.0044) and adult (P=0.001) compared to controls. Levels of anti-TTG and anti-GAD antibodies increased with increasing titre of anti-TPO antibody. Interpretation & conclusions: Our findings showed high positivity of anti-GAD and anti-TTG antibodies among subjects with thyroid autoimmunity. It is, therefore, important to have high clinical index of suspicion for celiac disease or type 1 diabetes mellitus in patients with autoimmune thyroiditis

Vitamin D status in healthy Indians aged 50 years and above

Introduction: There is widespread prevalence of Vitamin D deficiency from new-born to infancy, childhood and adult male and females (non-pregnant, pregnant and lactating). However, there is limited information of the vitamin D status in elderly Indians. Material and Methods: The study was carried in 1346 healthy subjects more than 50 years of age residing in Delhi, India. These subjects, who were divided in two groups: Group-1 (50 - &#60;65 years) and Group-2 (&#8805;65 years), underwent anthropometric, biochemical and hormonal evaluation for vitamin D status Bone mineral density was measured by dual X-ray absorptiometry. Results: There were 643 males and 703 females, with a mean age of 58.0 &#177; 9.5 years (range 50-84 years). Vitamin D deficiency [VDD, serum 25(OH)D levels &#60; 20 ng/ml) was present in 1228 (91.2%) and Vitamin D insufficiency [VDI, serum 25(OH)D levels 20-&#60;30 ng/ml] in 92(6.8%). There was no significant difference in prevalence of either VDD or VDI between two age groups and sexes. Serum 25(OH)D levels were negatively correlated with PTH levels (r -0.027, p &#60;0.00001) and BMI (r -0.128, p 0.05). Prevalence of secondary hyperparathyroidism increased from 14.1% to 43.1% from VDI to severe VDD. PTH levels started rising at vitamin D level &#60; 30 ng/ml. However, more than 50% of subjects with severe VDD had PTH levels within normal range. High prevalence of osteopenia (50.2%) and osteoporosis (31.2%) was observed in this population. Conclusion: Hypovitaminosis D is universal above the age of 50 years in north India. Absence of a PTH response was observed in more than 50% of individuals with VDD, the cause of which merits further evaluation. Normal bone mass was observed in only 18.6% of study subjects

Status of thyroid function in Indian adults: two decades after universal salt iodization

Objectives: The aim was to find impact of two decades of universal salt iodization on the prevalence of goiter, thyroid autoimmunity and thyroid dysfunction in Indian adults. Methods: This was a cross sectional study from Delhi, India. The subject population included 4409 adult members of resident welfare associations of 5 residential colonies, from 18-90 years of age, who participated in general health check-up camps. The subjects underwent a detailed evaluation including history, anthropometry, goiter grading, USG thyroid, thyroid auto-antibodies and thyroid function tests. All these subjects were regularly consuming iodized salt. Results: Overall, 9.6 % of subjects had clinical goiter (13.3% women and 3.3% in men). Prevalence of nodules on palpation was found to be in 1.6% which was lower in men. The nodule prevalence increased to 4.6% in men and 5.6 % in women on ultrasonography. Thyroid hypoechogenicity was seen in 30.6% of subjects with severe hypoechogenicity higher in women (5.7% men and 15.5% women). TPO antibody was positive in 13.3% adults and it showed a positive correlation with age, female sex and hypothyroidism. Subclinical hypothyroidism was the commonest abnormality encountered and affected 19.3% subjects (15.9% men; 21.4% women). Thyroid dysfunction showed a rising trend with age in both genders. Conclusions: Normal UIE and low goiter prevalence, especially in males, suggest success of the universal salt iodization program in the region under review. High prevalence of subclinical hypothyroidism was not correlated with either thyroid autoimmunity or iodine intake, as reflected in urinary iodine excretion

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 &#8804; 18 years) and Group-2 (age &#62; 18 years) was undertaken. They were further subdivided on the basis of their thyroid functional status: Normal (Control); SCH with TSH &#8804; 10.0 mIU/L (SCH-1); and SCH with TSH &#62; 10 mIU/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 &#62; 10 mIU/L compared with controls. Serum total cholesterol (TC) and LDL cholesterol (LDL) were significantly higher in adults with TSH &#62; 10 mIU/L compared to controls. There were no significant changes in lipid parameters in subjects with SCH having TSH &#8804; 10.0 mIU/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 &#62; 10.0 mIU/L), and not in subjects with SCH-1 who had TSH &#8804; 10.0 mIU/L in Indian population

Glutamic acid decarboxylase (anti-GAD) &#38; tissue transglutaminase (anti-TTG) antibodies in patients with thyroid autoimmunity

Background &#38; Objectives: Several autoimmune disorders have been reported to be associated with autoimmune thyroiditis and may coexist with other organ-specific autoantibodies. The aim of the present study was to evaluate the presence of Tissue Transglutaminase (anti-TTG) and Glutamic Acid Decarboxylase (anti-GAD) antibodies in patients suffering from autoimmune thyroiditis as diagnosed by anti-Thyroid Peroxidase (anti-TPO) antibodies, which may indicate high risk for developing celiac disease or type 1 diabetes mellitus. Methods: Five thousand children and 2800 adults were screening as part of a general health examination done on a voluntary basis in four different parts of Delhi. A total of 577 subjects positive for anti-TPO antibody constituted the cases. Equal number of age and sex matched anti-TPO antibody negative controls were randomly selected from the same cohort to form paired case control study. The cases and controls were further divided into two groups as follows: group-1 (children and adolescent &#60;18 yr), group-2 (adults &#62;18 yr). Serum samples of cases and controls were analysed for thyroid function test (FT3, FT4, and TSH), anti-TTG and anti-GAD antibodies. Results: A total of 1154 subjects (577 cases and 577 controls) were included in this study. Hypothyroidism was present in 40.2 per cent (232) cases compared to only 4.7 per cent (27) in controls (P&#60;0.001). Anti-TTG and anti-GAD antibodies were present in 6.9 and 12.5 per cent subjects among cases compared to 3.5 per cent (P = 0.015) and 4.3 per cent (P = 0.001) in controls, respectively. Only anti-GAD antibody were significantly positive in cases among children and adolescents (P = 0.0044) and adult (P = 0.001) compared to controls. Levels of anti-TTG and anti-GAD antibodies increased with increasing titre of anti-TPO antibody. Interpretation &#38; Conclusions: Our findings showed high positivity of anti-GAD and anti-TTG antibodies among subjects with thyroid autoimmunity. It is, therefore, important to have high clinical index of suspicion for celiac disease or type 1 diabetes mellitus in patients with autoimmune thyroiditis

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. Design and Subjects: All children (N = 9527; 6–19 years) from six schools representing various zones of Delhi were evaluated for clinical evidence of goitre, thyroid ultrasound, serum free T3 (FT3), free T4 (FT4) and TSH and anti-thyroid peroxidase (anti-TPO) antibodies. From this sample, a reference population (N = 5122) was obtained by excluding those with a personal or family history of thyroid disease, use of thyroid medications, goitre, hypoechogenicity/nodularity on ultrasound or serum anti-TPO antibodies. Measurements: Thyroid hormone (FT3, FT4 and TSH) reference ranges were established for each year of life for the total and reference populations. Results: In the reference population, mean serum FT3 was in the range 4.19–4.84 pM/l for boys and 4.03–4.47 pM/l for girls, mean serum FT4 14.69–17.36 pM/l for boys and 14.32–15.88 pM/l for girls and mean serum TSH 2.57–3.6 mIU/l for boys and 1.83–3.58 mIU/l for girls. For TSH, the 97th percentile was in the range 6.01–8.4 mIU/l for boys and 5.28–8.04 mIU/l for girls, suggesting that at least in children there may not be a need to reduce the upper limit of normal for serum TSH. Conclusions: This study provides mean reference intervals for FT3, FT4 and TSH for each year of life for both the sexes separately using strict exclusion criteria

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 &#177; 0.137, 0.755 &#177; 0.089, 1.129 &#177; 0.130 and 1.115 &#177; 0.133 g/cm2, 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 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