Physical Fitness Is Independently Related to Blood Leptin Concentration and Insulin Sensitivity Index in Male Subjects with Central Adiposity

Abstract

Aim: To compare the maximal power output (MPO) of subjects presenting a central adiposity to those of controls and to study the links between plasma leptin or indices of insulin sensitivity (QUICKI) and physical fitness (PF). Methods: MPO was determined for 169 middle-aged men divided into two groups according to waist circumference (WC– < 94 cm, WC+ ≧ 94 cm) each subdivided in two subgroups with low and high PF (WC-L, WC-H, WC+L, WC+H) determined from the median MPO relative to fat free mass (3.06 W/kg_FFM). Results: MPO (W/kg_FFM) was lower in WC+ than in WC–. Expressed relative to fat mass, leptin was lower and QUICKI higher in WC– than in WC+. In WC+H, leptin and QUICKI were significantly less disturbed than in WC+L and were independently correlated to MPO (r = –0.36 and r = 0.32 respectively; p < 0.001). In WC+, when visceral perimeter was added to the analysis, the relationships MPO/leptin remained significant but not MPO/QUICKI. Conclusion: The low PF in subjects with abdominal obesity is independently linked to plasma leptin and insulin sensitivity even if leptin and insulin may share common pathways in their peripheral effects. Visceral adiposity participates to the link between MPO and QUICKI, but not between MPO and leptin.

In middle-aged and old obese patients, training intervention reduces leptin level: A meta-analysis

“…Among the 19 studies ( Table 1 ), 18 applied training intervention [ 32 – 45 , 47 – 50 ], one compared the leptin levels of a mildly obese sedentary and a physically active group with similar BMI [ 46 ]. Regarding training, 13 studies applied a single (10-week to 6-month) training period [ 32 , 35 , 36 , 39 , 40 – 45 , 48 – 50 ], while 5 studies applied a 2-phase, 12-18-month training with the first leptin test after the first 3 or 6 months [ 33 , 34 , 37 , 38 , 47 ].…”

“…Regarding gender, 6 studies reported data of men [ 36 , 40 , 41 , 43 , 44 , 46 ], 5 reported data of women [ 32 , 35 , 37 , 38 , 50 ], the remaining 8 merged data of men and women [ 33 , 34 , 39 , 42 , 45 , 47 – 49 ].…”

Testosterone and Adipokines are Determinants of Physical Performance, Strength, and Aerobic Fitness in Frail, Obese, Older Adults

“…Leptin stimulates fatty acid oxidation in skeletal muscles and inhibits fat storage while promoting intramuscular lipolysis [35, 36]. Nevertheless, despite this positive effect of leptin on muscle metabolism, epidemiologic studies demonstrate a negative association between leptin with muscle mass and function [13, 37]. This inconsistency is believed to result from leptin resistance that develops with high-fat feeding and obesity [38, 39].…”

“…Briefly, the incremental test started at a speed determined, during a warm-period, to elicit ~70% of age-predicted HR max⁡ , and the speed remained constant throughout the test, while the grade was increased by 2% every 2 minutes. The test continued until the subject could no longer exercise because of exhaustion or until other conditions, such as ECG changes or development of symptoms, made it unsafe to continue [12, 13]. …”