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opinion a < 140/<90 mmHg goal is recommended. This variability contributes to
further confusion about the epidemiology and consequences of treatment-resistant
hypertension in the elderly.
Prevalence of Resistant Hypertension in Elderly People
with Chronic Kidney Disease
A recent study found that 13% of hypertensive patients met the American Heart
Association criteria for resistant hypertension [ 11 ]. However, the incidence mark-
edly differed by age: 5.5% for those <50 years (8.5% men and 3.2% women) and
25% of those >80 years (16% of men and 31% of women). In patients <50 years,
resistant hypertension was associated with male sex, obesity, and chronic kidney
disease, while in those >80 years, resistant hypertension was associated with female
sex diabetes mellitus, obesity, and chronic kidney disease. Chronic kidney disease
was the common element. Resistant hypertension in chronic kidney disease has
been recently reviewed in depth [ 6 ]. However this review raised more questions
regarding this subject, especially in the elderly.
The prevalence of true resistant hypertension is unknown because most studies
did not include key diagnostic criteria (e.g., antihypertensive medication doses,
treatment adherence, and systematic exclusion of measurement artifacts) [ 6 ].
Estimates vary widely: 0.5–14% of people treated for hypertension have apparent
treatment-resistant hypertension. However, this reflects apparent treatment-resistant
hypertension since in the general population, only 50% of patients with apparent
treatment-resistant hypertension have been prescribed optimum antihypertensive
therapy. Moreover, 40% of apparent treatment-resistant hypertension could be
white-coat hypertension or caused by medication nonadherence. Indeed, nonadher-
ence is extremely hard to detect and even more so in large epidemiological study.
Etiology
The etiology of resistant hypertension in elderly patients with chronic kidney dis-
ease is most likely chronic kidney disease, the most frequent cause of secondary
hypertension. It is still possible that elderly chronic kidney disease patients have a
low frequency cause of secondary hypertension. However, in the context of chronic
kidney disease and old age, most likely this will not be searched for in routine clini-
cal settings. In this regard, three issues merit discussion: the cause and effect rela-
tionship between chronic kidney disease and hypertension, dietary habits, and
noncompliance.
Hypertension is widely acknowledged to be the second major cause of end-stage
renal disease after diabetes [ 12 , 13 ]. However, recent genetic evidence has uncov-
ered a mutation in the APOL1 gene as the cause of nephropathy in a majority of
R. Fernández-Prado et al.