Thyroid Stimulating Hormone Within the Reference Range is Associated with Visceral Adiposity Index and Lipid Accumulation Product: A Population-Based Study of SPECT-China.

Few studies about the relationship of thyroid stimulating hormone (TSH) level with visceral adiposity index (VAI) and lipid accumulation product (LAP) in large Chinese population are available. The aim of this study was to explore whether TSH level within the reference range was associated with these two newer reliable cardiovascular risk factors. The data were obtained from a cross-sectional study (SPECT-China study, 2014-2015), which was based on the population. Participants underwent several checkups, which included anthropometric parameters, blood pressure, TSH levels, and glucose and lipid profiles. VAI and LAP were calculated. A total of 8727 subjects were enrolled in this study. The mean age was 53.00±13.05 years. Age, female to male ratio, BMI, systolic pressure, and HOMA-IR increased along with the increasing levels of TSH (p<0.01). Analysis of lipid profile showed significantly higher serum triglycerides and LDL cholesterol levels in the higher TSH quartile (p<0.001 and p=0.028, respectively). The levels of VAI and LAP were all increased along with increasing TSH level (all p<0.001). After full adjustment, TSH levels were positively associated with VAI, LAP, and TG/HDL levels significantly (B=0.041, 0.028 and 0.037, respectively, all p<0.01). Higher TSH concentrations among the reference range were common in older people as well as in women subjects, and they were positively associated with VAI and LAP. This highlighted that even subtle variations of serum TSH within the normal range may be potential risk factors for cardiovascular diseases.