Leptin is independently associated with systolic blood pressure, pulse pressure and arterial compliance in hypertensive African women with increased adiposity: the POWIRS study.
High leptin levels are often observed in human obesity and are implicated in obesity-related hypertension. Leptin levels have been found to be higher in hypertensive obese African-American women compared to normotensive African-American women, but a direct association between leptin and blood pressure could not be obtained. Additionally, increased adiposity has been associated with higher aortic stiffness in obese African-American women, but leptin was not included in the study. The effects of leptin on cardiovascular function in African women have not yet been determined. We hypothesised that leptin is directly associated with blood pressure and decreased arterial compliance and that leptin levels are significantly higher in hypertensive overweight/obese African women compared to normotensive overweight/obese African women. A case-case control study was performed which included 98 African women. The subjects were divided into lean normotensive (lean NT), overweight/obese normotensive (OW/OB NT) and overweight/obese hypertensive (OW/OB HT). The Finometer apparatus was used to obtain a more elaborate cardiovascular profile. Serum leptin and insulin levels as well as the HOMA-IR index were determined. Various anthropometric measures were obtained. Leptin levels were elevated (P < or = 0.05) in the OW/OB NT and HT groups compared to the lean NT group, but were similar in the OW/OB NT and HT groups. After adjusting for obesity, insulin resistance, hyperinsulinaemia and age, a direct positive correlation was obtained between leptin and systolic blood pressure (SBP) (P < or = 0.05; r = 0.68) in the OW/OB HT group. Additionally, leptin also correlated negatively with arterial compliance (P< or = 0.05; r = -0.76) and positively with pulse pressure (P < or = 0.05; r = 0.71) in the OW/OB HT group. In conclusion, even though leptin levels were the same in OW/OB HT and NT African women, leptin was directly and positively associated with SBP and pulse pressure and negatively with C(W) only in OW/OB HT African women, independent of obesity, insulin-resistance, hyperinsulinaemia and age.
Schutte
R
R
School of Physiology, Nutrition and Consumer Sciences, North-West University, Potchefstroom, South Africa. flgrus@puknet.puk.ac.za
Huisman
H W
HW
Schutte
A E
AE
Malan
N T
NT
D000328:Adult; D015415:Biomarkers / Q000097:blood; D044383:Black People; D001794:Blood Pressure / Q000502:physiology*; D015992:Body Mass Index; D016022:Case-Control Studies; D003187:Compliance; D016001:Confidence Intervals; D005260:Female; D006801:Humans; D006973:Hypertension / Q000097:blood* / Q000208:ethnology / Q000503:physiopathology; D020738:Leptin / Q000097:blood*; D009765:Obesity / Q000097:blood* / Q000208:ethnology / Q000503:physiopathology; D011674:Pulse; D013019:South Africa / Q000208:ethnology; D013599:Systole; D001741:Black or African American
D015415:Biomarkers; D020738:Leptin