Sodium-lithium countertransport and hypertension in Rochester, Minnesota.

Abstract

The objectives of the present study were to determine whether increased sodium-lithium countertransport is associated with essential hypertension in the general Caucasian population and to determine whether this association is independent of the effects of gender, age, body size, and plasma lipids. We studied 543 men and 589 women from the population of Rochester, Minnesota. Mean sodium-lithium countertransport was higher in hypertensive than in normotensive subjects in men (370±147 [mean±SD] versus 315±110 jtmol/1 red blood cells [RBC]/hr, p<0.001) and in women (339±114 versus 269±92 fimol/l RBC/hr, /><0.001). Interindividual differences in plasma triglycerides, body mass index (wt/[ht]2 ), and plasma total cholesterol explained 13.0% of sodium-lithium countertransport variation in men (/><0.001) and 20.2% in women (/><0.001). Age did not predict additional sodium-lithium countertransport variation in either gender. Slopes of the regressions of sodium-lithium countertransport on plasma triglycerides, body mass index, and plasma total cholesterol did not differ between diagnostic groups in men (p=03l) or in women (p=0J29). After adjustment to remove sodium-lithium countertransport variation attributable to these covariates, mean sodium-lithium countertransport remained significantly higher in hypertensive than in normotensive subjects in men (354±139 versus 319±104 /i.mol/1 RBC/hr, p<0.01) and in women (311 ±103 versus 278±83 /imol/1 RBC/hr, p<0.01). These findings in a large sample from Rochester, Minnesota, support the conclusions that increased sodium-lithium countertransport is associated with essential hypertension in the general Caucasian population and that this association is independent of the effects of gender, age, body size, and plasma lipids. Additional studies are necessary to establish whether sodium-lithium countertransport is an independent predictor of risk of developing essential hypertension. {Hypertension 1991;18:183-190) S odium-lithium countertransport has been proposed as an indicator of inherited predisposition to essential hypertension. This proposal is based on the finding of higher mean sodium-lithium countertransport in Caucasian patients with hypertension and in their young, hypertensive-prone offspring than in selected normotensive controls.1 However, since the samples for most previous studies were small and were ascertained through referral clinics or hospitals, their findings may not be representative of the community at large. Furthermore, many characteristics other than blood pressure differ between hypertensive and normotensive individuals, and some of these vari-

Variation in the Region of the Angiotensin-Converting Enzyme Gene Influences Interindividual Differences in Blood Pressure Levels in Young White Males

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Parameters of Lymphocyte Na + -Ca 2+ Regulation and Blood Pressure

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Prospective Analysis of Traits Related to 6-Year Change in Sodium-Lithium Countertransport

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