Evaluation response and effectiveness of thyroid hormone replacement treatment on lipid profile and function in elderly patients with subclinical hypothyroidism

Abstract

Positive effect of thyroid hormone replacement (THR) on lipid profile is well defined. Effectiveness of THR on lipid profile and function among elderly patients with subclinical hypothyroidism (SCH) has not yet been concluded. This is a population-based cross-sectional study. Twenty-six elderly patients with SCH were compared with 31 patients with clinical hypothyroidism (CH). Before the study neither group had received THR therapy. Data on lipid profile, demographic, functional, and cognitive status were obtained at baseline. SCH was defined as an elevated thyroid-stimulating hormone (TSH) level (>4.67 mU/l) and normal serum free thyroxine (FT 4) level. Total cholesterol (TC), high-density lipoprotein (HDL) cholesterol, and triglycerides (TG) were measured after overnight fast. The level of lower density lipoprotein (LDL) cholesterol was calculated. Both studied groups received levothyroxyne replacement and re-evaluated after 3 months of euthyroidism. Functional and cognitive status were evaluated by the activity of daily living (ADL) and mini mental state evaluation (MMSE), respectively. Participants with SCH did not differ from patients with CH regarding age, gender, cognitive, and functional status, and prevalence of cardiovascular disease (CD) was similar in both groups. Most patients (24/26) with SCH had TSH levels lower than 10 mU/l. Response to THR therapy regarding the improvement of blood levels of TC, LDL, and TG had a non-significant trend, which seemed to be better in patients with SCH than in those with CH. Decreases, TC/HDL and LDL/HDL ratios were greater in patients SCH ( p < 0.0001 and p = 0.0004, respectively) than in patients with CH. Improvement in cognitive and functional status and decrease in mean blood pressure and body mass index (BMI) were found in both of studied groups. It was shown that THR among patients with SCH is beneficial not only by improvement in lipid profile, as well as by improvement in cognitive and functional status, but also in decreasing blood pressure and BMI.