ABSTRACT
The elderly, defined as individuals 65 years of age and older, represent the most rapidly growing segment of the population. Accounting for 13% of the United States population in 1990, they are expected to account for 20% of the population by the year 2040. The percentage of those over age 85 is projected to reach 16 million over the same time period.1 More than 50% of the population older than 60 years of age have hypertension, defined as a systolic blood pressure (SBP) 140 mmHg and a diastolic blood pressure (DBP) 90 mmHg, approaching 75% in those over age 75 (Table 3.1).2 Of the 50 million hypertensives in the United States, only 1 out of every 4 have their blood pressure controlled (i.e. 140/90 mmHg). Control rates are even worse in the elderly3 (Figure 3.1). A recent trial found that only 7% of hypertensive patients 65 years of age and older enrolled in a large Health Maintenance Organization were on treatment and had their blood pressure controlled to 140/90 mmHg.4 Many cardiovascular risk factors including obesity, sedentary lifestyle, hyperlipidemia, diabetes, and left
ventricular hypertrophy remain more common among the elderly with hypertension than among those of younger age. These are well known to the practicing physician. What is not as well appreciated is that over 6 million Americans are estimated to have abnormally high serum creatinine and are at risk for progressive nephropathy.5 Current estimates predict as many as 600 000 Americans will develop end-stage renal disease (ESRD) by the year 2010.6
The kidney and hypertension are closely related. Up to 85% of patients with kidney disease have hypertension and hypertension contributes to the progressive decline in renal function. The elderly continue to have a much higher morbidity and mortality in those with underlying renal disease than their middle-aged and younger counterparts. In addition, analysis of recent trials suggest that renal functional decline significantly influences cardiovascular prognosis. A 24 hour urine sample should be collected in which both creatinine and albumin are detected to evaluate the adequacy of the collection. Nephropathy is diagnosed by either an
Introduction • The importance of systolic hypertension • isolated systolic hypertension (ISH) • Treatment of hypertension in the elderly is beneficial • The approach to the elderly hypertensive with renal insufficiency • Strategies for slowing progressive renal failure in patients with hypertension Selection of antihypertensive drugs • The j-curve phenomenon • Conclusion • References
increase in serum creatinine, or an increase in urinary albumin excretion. When the amount of protein excreted is greater than 30 mg but below 300 mg per gram of creatinine in a spot urine sample or 30-300 mg of albumin in a 24 hour sample, microalbuminuria is diagnosed. When there is more than 300 mg of albumin excreted, macroalbuminuria is detected
(Table 3.2). These abnormalities in renal function, including the presence of microalbuminuria, are potent predictors for the future development of ESRD,7 as well as cardiovascular disease and mortality in those with and without hypertension (Figures 3.2, 3.3, Box 3.1).8,9 In the Heart Outcomes Prevention Evaluation (HOPE) trial, the development of renal insufficiency
1988-91: NHANES III
Males Females
Age (yrs) African Mexican African Mexican American Causcasian American American Causcasian American
18-29 6.4 3.3 3.4 2.3 1.0 0.9 30-39 22.5 13.2 7.6 11.2 6.9 4.4 40-49 35.2 22.0 24.8 33.2 11.3 10.5 50-59 53.3 37.5 38.4 47.8 33.0 28.8 60-74 71.2 51.1 44.3 73.9 50.0 53.0
* Numbers at top of bars represent the overall percentage distribution among the inadequately treated by age.
