Abdominal obesity is characterized by higher pulse pressure: possible role of free triiodothyronine

Objective. This study examined whether obesity is characterized by higher 24 h mean pulse pressure (24 h mean SBP-24 h mean DBP) and whether free thyroid hormones (FT(3) and FT(4)) have a relationship with 24 h mean pulse pressure. Methods. A total of 231 euthyroid overweight and obese patients, 103 women and 128 men, aged 18-68 yrs, normotensive (n = 69) or with recently developed hypertension (n = 162), never treated with antihypertensive drugs, were investigated. Fasting insulin, TSH, FT(3), FT(4), glucose, and lipid serum concentrations were measured. Waist circumference was measured as an indirect parameter of central fat accumulation. Ambulatory blood pressure monitoring (ABPM) was performed. Results. 24 h mean pulse pressure (PP) showed a significant positive correlation with BMI (P < 0.001), waist circumference (P < 0.001), and FT(3) (P < 0.001) and insulin serum levels (P < 0.05). When a multivariate analysis was performed, and 24 h PP was considered as the dependent variable, and waist circumference, FT(3), insulin, male sex, and age as independent parameters, 24 h mean PP maintained a significant association only with waist circumference (P < 0.001) and FT(3) levels (P < 0.05). Conclusion. Our results suggest that FT(3) per se may contribute to higher pulse pressure in obese subjects.