Red blood cell Na content, Na, Li-countertransport, family history of hypertension and blood pressure in school children.

This study focuses on the relationship between some aspects of intra-erythrocytic sodium metabolism (intra-erythrocytic Na content, Na,Li-countertransport), blood pressure, and family history of hypertension, in a group of 84 randomly selected school children (45 males, 39 females). Na,Li-countertransport was significantly related to both systolic blood pressure (SBP) and diastolic blood pressure (DBP) only in boys at the univariate level, but both of these associations lost statistical significance after the possible confounding role of weight and height were taken into consideration. In both sexes, participants with a family history of hypertension had similar values of both intra-erythrocytic Na content and Na,Li-countertransport to participants with no family history. We conclude that family history of hypertension does not seem to play an important role in the determination of either intra-erythrocytic Na content or Na,Li-countertransport at this age. Although the positive association between Na,Li-countertransport and blood pressure observed in adult males is already present in childhood, this probably is still, at least in part, dependent upon body size.

Outward Na-K-Cl cotransport in human red blood cells: a methodological evaluation of method for epidemiologic investigations.

The present report evaluates a method for the determination of the maximal velocity of the outward sodium, potassium, chlorine (Na-K-Cl) cotransport in erythrocytes. The loading procedure was carried out using the ionophore nystatin. The technical error for this assay, based on concurrent analysis of randomized blind duplicate samples, was 8.04% of the sample mean and 27.5% of the sample standard deviation. The assay was stable over time and reproducible. Fasting was not necessary. The ratio of intra- to interindividual variances was small. The cells can be safely preserved in an appropriate preservation solution without modification of the ion transport assay. The assay appears to be adequate for use in large-scale field trials.

Alcohol consumption and blood pressure in school children.

The present report focuses on the relationship between alcohol consumption, estimated with the use of a seven day food record, and blood pressure in a group of 203 male and female school children with a mean age of 11 year. 50.5% of the male and 39.4% of the female children reported use of alcoholic beverages. The average weekly ethanol consumption in these regular drinkers was 73.9 ml/week for boys and 53.1 ml/week for girls. The results of the analyses fail to show any significant association between alcohol consumption and blood pressure levels. The possibility of the association between alcohol and hypertension being dependent on advanced age is discussed in view of the present results and previously published reports.