Trends of Serum Thyrotropin Concentration and Associated Factors in Urban Pakistan (Karachi)

Abstract

Background:This investigation aimed at assessing trends of TSH levels and associated factors in apparently normal subjects of urban Pakistan (Karachi).Materials and Methods: The survey was conducted in 2004 in Lyari, Karachi. Using a geographical imaging system, 85, 520 households were identified, of which 532 were randomly se-lected; 867 adults aged ≥25 years consented to take part in the study. Blood samples from 324 subjects were available for analyses. Subjects with previous history of thyroid disorders were excluded.Results: Mean age of subjects was 40.8±14.13 years; 68.2% were females; mean values of waist circumference of males and females were 89.5±16 cm and 87.8±15.7 cm respectively. Fifty-nine (18.2%) subjects had TSH>6.0 (mU/L) based on the ELISA laboratory reference range, used for the estimation of TSH. Based on the American Thyroid Association (ATA) guidelines, 159 (49.07%) subjects had TSH23) and elevated serum TSH concentration (TSH>4.1 mU/L) was also observed.Conclusion: This spectrum of TSH levels highlighted a high prevalence of increased serum TSH levels in the population studied, a trend that was associated with obesity and various lipid abnormalities. Further population based studies are needed to correlate these findings with clinical parameters of hypothyroidism.