https://imcjms.com/public Ibrahim Medical College Journal of Medical Science https://imcjms.com/public/registration/journal_full_text/327 Wed, 24 Jul 2019 00:32:15 +0000 Background and aims: Hypothyroidism is a common global endocrine disorder. The magnitude of hypothyroidism at community level in Bangladesh is unknown except some clinic-based studies. The present study was undertaken to determine the prevalence of hypothyroidism in different occupational groups of Bangladeshi population and to assess the risks related to it. Results: Overall, 626 (M/F=123 / 503) participants with a mean age of 35.9 (34.75 – 37.02) years volunteered. The mean values of all participant for TSH and FT4 were 2.08 (95%CI: 1.72 – 2.45) μiu/ml and 13.04 (95CI:12.86 – 13.22) pmol/L respectively. The third percentile of TSH ranged from 0.42 to 0.46 μiu/ml and 97th percentile ranged from 5.16 to 5.24 μiu/ml. For FT4, the 3rd and the 97th percentile were 10.3 and 16.41 pmol/L, respectively. The prevalence of hypothyroidism in both sexes was 7.0% (M/F=4.1/8.3%). Occupational groups, sex and increasing age, obesity, blood pressure, and lipids showed no association with hypothyroidism. Hyperglycemia was proved to be a significant risk for hypothyroidism (prevalence in diabetic vs. non-diabetic was12.9% vs. 5.5%, p = 0.04; FBG was correlated with TSH, r = 0.138, p <0.001). IMC J Med Sci 2019; 13(2): 002. EPub date: 24 July 2019. DOI: https://doi.org/10.3329/imcjms.v13i2.45275     We investigated the trend of prevalence of hypothyroidism according to quartiles (Q 01 through Q04) of age, BMI, WHtR, FBG in Figure-1. The measures of central tendencies and variability of thyroid stimulating hormone (TSH) and free thyroxin (FT4) are shown in Table-7. The prevalence did not increase significantly with increasing age, BMI, WHtR; whereas, the trend was significant for increasing level of FBG (p=0.04).   Fig-1: Trend of hypothyroidism prevalence according to quartiles of age, BMI, WHR, WHtR, FBG. The trends of prevalence (%) for age-quartile, BMI-quartile were not significant, whereas, FBG-quartile was found significant (p=.04). The quartiles of central obesity measures (WHR) were not significant (not shown in the figure).   Table-7: Statistics measures of central tendencies and variability of thyroid stimulating hormone (TSH) and free thyroxin (FT4)   Hypothyroidism is based only on the circulating blood level of TSH despite normal FT4 level, and the clinical manifestations are usually not evident. This study is unique in the sense that it addressed the prevalence of subclinical hypothyroidism at community level. Additionally, it investigated whether the risk factors, so far known, are associated with hypothyroidism in our population. Simultaneously, this study included different occupational groups for comparison of prevalence rates and the associated risk factors acting upon the occupational groups. The study could propose the values of TSH and FT4 at 3rd and 97th percentile (Table-1). This finding may help to compare or to determine future reference range of TSH and FT4. Regarding diabetes, the prevalence of hypothyroidism was significantly higher among the diabetic than among the non-diabetic group (Table-3). Correlation was also found significant between FBG and TSH (Table-5). Additionally, we found that the trend of hypothyroidism increased significantly with increasing fasting blood glucose (Figure-1). The associations between hypothyroidism and diabetes have been reported in other studies and in other forms of diabetes [6, 7, 18-22]. A study found a higher TSH level in patients with metabolic syndrome suggesting that hypothyroidism may be a risk factor for it [23]. In subclinical hypothyroidism, insulin resistance may result from diminished rate of insulin stimulated glucose transport caused by perturbed expression of glucose transporter type 2 genes (GLUT 2). There is also impaired insulin stimulated glucose utilization in peripheral tissues [24]. The study has some limitations. Had we clinically examine those who had high TSH level we could have identified the common signs or symptoms related to hypothyroidism which could help physician to look into clinical features cautiously. Secondly, we could have assayed free tri-iodothyronine (FT3), thyroid peroxidase antibody (anti-TPO) and reverse thyroxine (rt3) for more reliable thyroid dysfunction. 2026 Ibrahim Medical College. All rights reserved.