Relationship between leptin resistance and obesity-related hypertension in elderly men

Hongyi XING; Hao ZHAN; Yuanwu MEI; Guirong WEI

ABSTRACT

BACKGROUND:

It has been known that there exists a close relationship between leptin and obesity.Then,how are serum leptin and insulin related to obesity-related hypertension(ORH)?

OBJECTIVE:

To study the changes of serum leptin and insulin in elderly men with ORH,and investigate the relationship between leptin resistance and ORH in elderly men.

DESIGN:

Retrospective controlled study based on diagnosis. SETTINGSThe Department of Neurology and the Department of Nuclear Medicine,Affiliated Union Hospital of Tongji Medical College, Huazhong University of Science and Technology.

PARTICIPANTS:

Altogether 62 elderly male inpatients or outpatients aged from 60 to 82 years in the Affiliated Union Hospital of Tongji Medical College from October 2001 to June 2002 were selected.The diagnosis of hypertension was based on the diagnostic criteria established by the WHO in 1999systolic blood pressure(SBP) ≥ 140 mm Hg(1 mm Hg=0.133 kPa) and(or) diastolic blood pressure(DBP) ≥ 90 mm Hg.

INTERVENTIONS:

The content of serum leptin and insulin in 41 hypertensive and 21 normotensive elderly men was determined by the method of radioimmunoassay. MAIN OUTCOME

MEASURES:

Blood pressure,body mass index (BMI),serum leptin and insulin level.

RESULTS:

The content of serum leptin and insulin in the hypertensive obese men were increased significantly by 1.8 μ g/L and 2.7 mIU/L,respectively,as compared with that in the normotensives (t=2.212,2.395,P< 0.01). The level of serum leptin and insulin in the ORH patients was increased by 2.7 μ g/L and 4.7 mIU/L,respectively,as compared with that of the normotensives with significant differences (t=3.348,5.113,all P< 0.001). The level of serum leptin in the hypertensive patients older than 70 years was significantly increased by 1.7 μ g/L compared with that of those aged 60 to 70 years(t=2.767,P< 0.05).

CONCLUSION:

Resistance to leptin and insulin exists in obesity-related hypertension of elderly men and leptin is closely associated with obesity-related hypertension.