African Americans sodium sensitivity

Race definitely comes into play. High blood pressure is far more common in blacks than in any other racial group, and it hits at an earlier age. But we know that African Americans are far more sodium sensitive than whites are and at the same time they have diets that are high in sodium, doubling the problem. The solution seems pretty obvious. Similarly, obesity and diabetes are more prevalent among blacks. Rather than wringing his or her hands in despair, the wise black individual will take appropriate action. 

Within those groups, however, were men and women who were very sensitive to sodium. Salt or sodium sensitivity is a very real thing. Researchers are now trying to develop a test for such sensitivity so that physicians can know which patients need sodium restriction and which do not, rather than prescribing it for everyone. That test is still in the future, but the zealots say we don t need such a test because if everyone greatly restricted sodium intake, some people would benefit and society would be the better for it. Maybe some day we ll have that sensitivity test, and maybe not. In the meantime, we do know that African Americans, older individuals,... 

Certain population groups are also served better by particular drugs. Studies have found and physicians have observed over the years that people who are sodium sensitive and/or who are members of an ethnic group such as African Americans whose diet is heavy on salt will frequently do best with diuretic drugs, calcium channel blockers, or both. 

Ssalt-sensitive people tend to develop hypertension with an intake of 125 to 250 mmol of Na per day, whereas salt-resistant people may not have a rise in blood pressure with up to 500 irunol of Na per day. Very large amounts of Na (800 mmol/day) lead to hypertension in both salt-sensitive and -insensitive people. It has been estimated that close to 20% of adult Americans lire salt sensitive. African-Americans have a greater incidence of Na sensitivity and hypertension than Americans of European descent. Generally, blood pressure tends to increase with age in salt-sensitive individuals consuming mrrderate or high levels of sodium. The prevalence of hypertension is very low in children and adolescents. The interracial differences in blood pressure that are found in adults arc not found among children (Sinaiko, 1996). 

Essential hypertension is a symptom of modem society, and its treatment accounts for a sizeable portion of global prescriptions. As a result, there is a great interest in reported ethnic and racial differences reported in the literature. The use of appropriate therapy in Black patients has been best studied. As monotherapy, calcium channel blockers and diuretics appear to be most effective in Blacks, whereas P-blockers and ACE inhibitors produce smaller reductions in blood pressure (Kiowiski et al, 1985 Freis, 1986 Hall, 1990). However, this may more reflect the lower plasma renin, salt and water retention and intercellular sodium and calcium in Blacks, compared to other groups (Kiowiski et al., 1988). There are individual exceptions amongst patients and among drugs, even within these classes for example labetalol, a combined a-blockers and P-blockers, can be equally effective in both African-Americans and Caucasians and, as mentioned previously, the Chinese appear twice as sensitive to propranolol as Caucasians (Oster etal., 1987 Zhou etal., 1990). 

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