Is geriatrics a primary care or subspecialty discipline?
The vast majority of care provided to older persons by geriatricians is primary care, and these physicians should be considered as generalists for health policy and educational purposes.
Low levels of plasma renin substrate can be considered as an indirect index of the severity of heart failure that reflects both the high level of circulating active renin and the decrease in hepatic protein output. In patients with class IV heart failure, low levels of renin substrate led to a marked underestimation of active renin concentration from measurements of PRA. In contrast, direct IRMA of active renin measures the true plasma active renin concentration, independent of plasma renin substrate, and closely reflects renin secretion.