体重与年龄对男性血清瘦素水平昼夜节律性的影响

Effect of body weight and age on circadian rhythm of serum leptin level in men

目的 研究成年男性血清瘦素水平的昼夜节律性和分析年龄、体重对血清瘦素水平的影响。方法 26名健康志愿者分为正常体重组(20人)和超重组(6人),按年龄将正常体重组再分为30岁、40岁、50岁和60岁组。白天(8:00～22:00)每2小时,夜间(22:00～8:00)每小时采血一次,放免法检测瘦素。结果 瘦素分泌呈昼夜节律性变化,高峰在夜间,超重组和50岁以上人中昼夜节律性及夜间分泌高峰更为明显,超重组、50岁和60岁组瘦素水平高于30岁和40岁组(P<0.05)。结论 男性血清瘦素水平及昼夜节律性受体重和年龄的影响,随体重增加和年龄增长血清瘦素水平有明显增高的趋势。

Objective To study the circadian rhythm of serum leptin levels and the influence of body mass index ( BMI) and age on serum leptin. Methods Serum leptin levels were studied on a circadian basis in 26 adult healthy men aged from 31 to 63 years, including 6 overweight ( BMI(29.4±1.5) kg/m2,age (43.3±14.3) years],and 20 with normal weight[ BM1(24.4±2.5)kg/m2, age(48.6±10.9)years].The normal-weight men were further divided into four age subgroups:i.e.,30 s, 40 s, 50 s, and 60 s. Serum samples were obtained at 2 h interval from 8 :00 to 22:00 and 1 h interval from 22 :00 to 8 :00 for 24 h. Serum leptin level was measured by RIA and the circadian variations and the group-related differences were analyzed with student t-test and ANOVA, the circadian rhythmicity was further analyzed with chronobiological cosinor method as well. Results A significant circadian rhythm of serum leptin levels was found in all groups with a peak at night. A statistically significant circadian rhythm (P<0.01) was validated in the overweight group (n=6) and in the normal-weight age subgroups of 50s and 60s. The circadian leptin levels were significantly higher in overweight group and the older normal-weight age subgroups of 50s and 60s (P<0.01 and P<0.05) when compared with that in younger age subgroups of 30s and 40s. Conclusion Body weight and age influence serum leptin level and its rhythm, and serum leptin level increases with advancing age and increasing body weight.