Leptin and the Retinal Microvasculature in Young Black and White Adults: The African-PREDICT Study.

BACKGROUND: Leptin is a vasoactive peptide that has been linked to diseases associated with macrovascular deterioration. What is still uncertain is its involvement in the microvasculature. Since microvascular changes are presumed to precede macrovascular deterioration, we examined whether measures of the retinal microvasculature are associated with leptin in healthy, young Black and White individuals. METHOD: We included 283 Black and 289 White men and women (aged 20-30 years). We determined serum leptin, calculated central retinal artery and vein equivalents and arterio-venous ratio. We also measured retinal vessel responses to light flicker provocation. RESULTS: Black men were leaner and had lower leptin than White men, whereas Black women had increased adiposity and leptin compared to White women (all p<0.001). Black groups had narrower retinal arteries, and greater maximum arteriolar and venular dilations in response to light flicker than the White groups (p<0.001). Arterio-venous ratio associated negatively with leptin (all p≤0.044) in all groups (except Black women), but was lost upon adjustment for body mass index and other covariates. We found an inverse association between maximal venular dilation and leptin only in Black men in single and multiple regression analyses (Std ß= -0.22; R2=0.05; p=0.035). No associations were found between other retinal measures with leptin in the other groups. CONCLUSION: We found an independent, negative association between retinal vein dilation with leptin in healthy, young Black men, suggesting a potential detrimental role for leptin in regulating microvascular responses in a population group known to be at greater risk of cardiovascular disease development.

In vitro hemolytic effect of sulfadoxine/pyrimethamine and artemether/lumefantrine on malaria parasitized erythrocytes of female patients.

G6PD is an X-linked gene enzyme that protects erythrocytes from hemolysis when they are exposed to antimalarial drugs because of the effects of the free radicals generated by these drugs. We investigated the effects of Fansidar ™ (Sulfatoxine/Pyrimethamine) and Coartem ™ (Artemether/Lumefantrine) on the hemolysis of malaria parasitized female erythrocytes. Twelve (12) malarious patients attending the University of Benin Teaching Hospital, Benin City, Nigeria, were used in this study. Ten (10) apparently healthy female students from the Medical School, University of Benin, acted as control. Low, normal (the recommended adult dose) and high doses of Fansidar ™ and Coartem ™ were used to determine the percentage hemolysis by checking the absorbance of the various samples. Data was analyzed by the Student's t-test and ANOVA with p<0.05 indicating the level of significance. At low doses of Fansidar ™ and Coartem ™, no hemolysis occurred, while at normal doses, Fansidar ™ showed no hemolysis but significant hemolysis (p<0.05) was observed in the Coartem ™ group. At high doses, both FansidarTM and CoartemTM caused significant (p<0.05) hemolysis. High doses of both drugs and normal dose of CoartemTM caused significant hemolysis. There was no hemolysis observed in the normal dose of FansidarTM and low doses for both drugs, similar to the trend reported for male subjects.