Dietary potassium intake and renal handling, and their impact on the cardiovascular health of normotensive afro-caribbeans.

OBJECTIVE: Recent nutritional profiles of dietary intake have indicated a shift from the ancient diet to the Western diet. The ancient diet provided a high potassium and low sodium intake, which in turn leads to sodium conservation and potassium excretion. This change in the dietary intake is expected to affect potassium and sodium handling in the kidneys. Numerous studies have been done to emphasize the importance of sodium handling by the kidneys and its impact on cardiovascular health. This study will investigate potassium intake and handling, and its impact on the cardiovascular health of a sample of normotensive Afro-Caribbeans by the possible modulation of the renin angiotensin aldosterone system (RAAS). METHODS: A sample of 51 normotensive Afro-Caribbean participants was recruited for the study. Participants were observed over a two-day period in which they were given a 24-hour ambulatory blood pressure monitor and a container to collect blood pressure data and a 24-hour urine sample. Anthropometric measurements were noted. Urinary electrolytes and supine plasma renin activity (PRA) were determined from the 24-hour urine collection and a blood sample. Dietary potassium intake was estimated based on dietary intake observations and calculated based on the urinary potassium excretion. SPSS version 19 was used to analyse the data to make inferences. RESULTS: The daily potassium intake was observed to be 2.95 g/day and measured intake from the urinary potassium was between 4.95 and 7.32 g/day. Urinary potassium excretion was 3.66 (± 1.40) g/day. The urinary potassium excretion in the Afro-Caribbean sample in Barbados was higher than the other population samples. The averaged PRA of the participants (supine) was 0.778 (± 1.072) ng/mL/hour. The averaged nocturnal systolic blood pressure dip of the participants was 5.97 (± 4.324) %. There was no significant correlation between urinary potassium excretion, blood pressure, nocturnal systolic blood pressure dip and PRA. CONCLUSIONS: The Afro-Caribbean sample has an inadequate daily potassium intake based on the observed intake and recommended values, with a high urinary excretion of the electrolyte compared to other values in the literature. This high potassium excretion could have been partly due to low plasma renin activity levels in the study participants. As a possible consequence, an increase in the nocturnal peripheral resistance is a likely cause for the diminished systolic dip. The lack of correlations between dietary potassium excretion and the blood pressure parameters does not allow any firm inference of the electrolyte's handling and its impact on cardiovascular health in the normotensive Afro-Caribbean participants. However, further research is needed to get a more accurate daily potassium intake value, and a more statistically robust sample to assess whether potassium handling and blood pressure would be affected by a change in potassium intake.

Dietary potassium intake and renal handling, and their impact on the cardiovascular health of normotensive Afro-Caribbeans / Ingesta dietética de potasio y manejo renal, y su impacto en la salud cardiovascular de los normotensos Afrocaribeños

OBJECTIVE: Recent nutritional profiles of dietary intake have indicated a shift from the ancient diet to the Western diet. The ancient diet provided high potassium and low sodium intake, which in turn led to sodium conservation and potassium excretion. This change in the dietary intake is expected to affect potassium and sodium handling in the kidneys. Numerous studies have been done to emphasize the importance of sodium handling by the kidneys and its impact on cardiovascular health . This study will investigate potassium intake and handling, and its impact on the cardiovascular health of a sample of normotensive Afro-Caribbeans by the possible modulation of the renin angiotensin aldosterone system (RAAS). METHODS: A sample of 51 normotensive Afro-Caribbean participants was recruited for the study. Participants were observed over a two-day period in which they were given a 24-hour ambulatory blood pressure monitor and a container to collect blood pressure data and a 24-hour urine sample. Anthropometric measurements were noted. Urinary electrolytes and supine plasma renin activity (PRA) were determined from the 24-hour urine collection and a blood sample. Dietary potassium intake was estimated based on dietary intake observations, and calculated based on the urinary potassium excretion. SPSS version 19 was used to analyse the data to make inferences. RESULTS: The daily potassium intake was observed to be 2.95 g/day and measured intake from the urinary potassium was between 4.95 and 7.32 g/day. Urinary potassium excretion was 3.66 (± 1.40) g/day. The urinary potassium excretion in the Afro-Caribbean sample in Barbados was higher than the other population samples. The averaged PRA of the participants (supine) was 0.778 (± 1.072) ng/mL/hour. The averaged nocturnal systolic blood pressure dip of the participants was 5.97 (± 4.324) %. There was no significant correlation between urinary potassium excretion, blood pressure, nocturnal systolic blood pressure dip and PRA. CONCLUSIONS: The Afro-Caribbean sample has an inadequate daily potassium intake based on the observed intake and recommended values, with a high urinary excretion of the electrolyte compared to other values in the literature. This high potassium excretion could have been partly due to low plasma renin activity levels in the study participants. As a possible consequence, an increase in the nocturnal peripheral resistance is a likely cause for the diminished systolic dip. The lack of correlations between dietary potassium excretion and the blood pressure parameters does not allow any firm inference of the electrolyte's handling and its impact on cardiovascular health in the normotensive Afro-Caribbean participants. However, further research is needed to get a more accurate daily potassium intake value, and a more statistically robust sample to assess whether potassium handling and blood pressure would be affected by a change in potassium intake.

OBJETIVO: Los perfiles nutricionales recientes de ingesta dietética han indicado un cambio de la dieta antigua a la dieta occidental. La dieta antigua ofrecía un consumo alto de potasio frente a un consumo bajo de sodio, lo que a su vez llevaba a la conservación del sodio y a la excreción del potasio. Se espera que este cambio en la ingesta dietética afecte el manejo del potasio y el sodio en los riñones. Se han realizado numerosos estudios con el fin de enfatizar la importancia del manejo del sodio por los riñones y su impacto en la salud cardiovascular. Este estudio investigará la ingesta y manejo del potasio, y su impacto en la salud cardiovascular de una muestra de normotensos afrocaribeños mediante la posible modulación del sistema renina-angiotensina-aldosterona (SRAA). MÉTODOS: Una muestra de 51 participantes normotensos afrocaribeños fue reclutada para el estudio. Los participantes fueron puestos bajo observación por un período de dos días, en los que recibieron un monitor ambulatorio para registrar la presión arterial por 24 horas, y un recipiente para recoger los datos de la presión arterial, y una muestra de orina de 24 horas. Se observaron las mediciones antropométricas. Los electrolitos urinarios y la actividad de renina plasmática (ARP) en posición supina, se determinaron a partir de la orina de 24 horas y una muestra de sangre. La ingesta dietética de potasio fue estimada en base a las observaciones hechas de la ingesta dietética, y se calculó a partir de la excreción del potasio urinario. La versión 19 del SPSS fue utilizada para analizar los datos y hacer inferencias. RESULTADOS: Se observó una ingestión diaria de potasio de 2.95 g/día, y la ingestión medida a partir del potasio urinario estuvo entre 4.95 y 7,32 g/día. La excreción del potasio urinario fue 3.66 (± 1.40) g/día. La excreción del potasio urinario en la muestra afrocaribeña en Barbados fue mayor que en las otras poblaciones. La actividad ARP promedio (supina) de los participantes fue 0.778 (± 1.072) ng/mL/hora. La caída nocturna promedio de la presión arterial sistólica de los participantes fue (± 4.324) 5.97%. No hubo ninguna correlación significativa entre la excreción del potasio urinario, la presión arterial, la caída nocturna de la presión arterial sistólica, y la actividad ARP. CONCLUSIONES: Partiendo de la base del consumo observado y los valores recomendados, la muestra afrocaribeña presenta una ingesta diaria inadecuada de potasio, con una alta excreción urinaria de electrólito, en comparación con otros valores en la literatura. Esta elevada excreción de potasio podría haberse debido en parte a niveles bajos de actividad de renina plasmática en los participantes del estudio. Una posible consecuencia es el aumento de la resistencia periférica nocturna como causa probable del descenso sistólico. La falta de correlación entre los parámetros de la presión arterial y la excreción de potasio dietético no permite ninguna inferencia sólida del manejo del electrólito y su impacto sobre la salud cardiovascular en los normotensos afrocaribeños participantes. Sin embargo, es necesario investigar más a fin de obtener un valor más exacto de la ingesta diaria de potasio y una muestra estadísticamente más sólida para evaluar si el manejo del potasio y la presión arterial podrían ser afectados por un cambio en la ingesta de potasio.

Coinfection with hepatitis C virus, oxidative stress and antioxidant status in HIV-positive drug users in Miami.

BACKGROUND: The pathogenesis of HIV/hepatitis C virus (HCV) coinfection is poorly understood. We examined markers of oxidative stress, plasma antioxidants and liver disease in HIV/HCV-coinfected and HIV-monoinfected adults. METHODS: Demographics, medical history, and proof of infection with HIV, hepatitis A virus (HAV), hepatitis B virus (HBV) and HCV were obtained. HIV viral load, CD4 cell count, complete blood count (CBC), complete metabolic panel, lipid profile, and plasma concentrations of zinc, selenium, and vitamins A and E were determined. Malondialdehyde (MDA) and glutathione peroxidase concentrations were obtained as measures of oxidative stress. Aminotransferase to platelet ratio index (APRI) and fibrosis index (FIB-4) markers were calculated. RESULTS: Significant differences were found between HIV/HCV-coinfected and HIV-monoinfected participants in levels of alanine aminotransferase (ALT) (mean±standard deviation: 51.4±50.6 vs. 31.9±43.1 U/L, respectively; P=0.014), aspartate aminotransferase (AST) (56.2±40.9 vs. 34.4±30.2 U/L; P<0.001), APRI (0.52±0.37 vs. 0.255±0.145; P=0.0001), FIB-4 (1.64±.0.91 vs. 1.03±0.11; P=0.0015) and plasma albumin (3.74±0.65 vs. 3.94±0.52 g/dL; P=0.038). There were no significant differences in CD4 cell count, HIV viral load or antiretroviral therapy (ART) between groups. Mean MDA was significantly higher (1.897±0.835 vs. 1.344± 0.223 nmol/mL, respectively; P=0.006) and plasma antioxidant concentrations were significantly lower [vitamin A, 39.5 ± 14.1 vs. 52.4±16.2 µg/dL, respectively (P=0.0004); vitamin E, 8.29±2.1 vs. 9.89±4.5 µg/mL (P=0.043); zinc, 0.61±0.14 vs. 0.67±0.15 mg/L (P=0.016)] in the HIV/HCV-coinfected participants than in the HIV-monoinfected participants, and these differences remained significant after adjusting for age, gender, CD4 cell count, HIV viral load, injecting drug use and race. There were no significant differences in glutathione peroxidase concentration, selenium concentration, body mass index (BMI), alcohol use or tobacco use between groups. Glutathione peroxidase concentration significantly increased as liver disease advanced, as measured by APRI (ß=0.00118; P=0.0082) and FIB-4 (ß=0.0029; P=0.0177). Vitamin A concentration significantly decreased (ß=-0.00581; P=0.0417) as APRI increased. CONCLUSION: HIV/HCV coinfection is associated with increased oxidative stress and decreased plasma antioxidant concentrations compared with HIV monoinfection. Research is needed to determine whether antioxidant supplementation delays liver disease in HIV/HCV coinfection.

C-reactive protein: a poor marker of cardiovascular disease risk in HIV+ populations with a high prevalence of elevated serum transaminases.

Blood lipids and high-sensitivity C-reactive protein (hsCRP) are used to assess cardiovascular disease (CVD) risk. We evaluated in a cross-sectional design the relationship of hsCRP to markers of liver function (aspartate and alanine transaminases [AST and ALT, respectively]), CVD risk factors and HIV-disease progression markers in 226 HIV-1 sero-positive drug users. hsCRP showed a significant inverse relationship with ALT and high-density lipoprotein, independent of age, gender, viral load, CD4 cell-count and antiretroviral (ARV) use, and was not significantly associated with HIV-disease progression markers. Serum markers of liver damage, AST and ALT, were associated with lower hsCRP, total cholesterol, low-density lipoproteins and triglycerides. Elevated liver enzymes (> or =40 IU/L) were predictive of hsCRP levels that are considered a low risk for CVD. In conclusion, hsCRP may not be a reliable marker of CVD risk in populations with HIV at-risk for elevated liver enzymes due to high hepatitis B virus/hepatitis C virus prevalence and ARV use.