michigan hypertension core curriculum - State of Michigan

development of essential HTN can set in motion a self-perpetuating cycle of damage. Hypertension
causes kidney injury, which exacerbates HTN, causing further kidney injury. Of note, not all CKD
attributed to HTN is initially cause by HTN. There are likely many individuals, particularly young people
who develop unrecognized, self-limited glomerular disease that results in kidney injury and HTN. For
these individuals with asymptomatic initial kidney injury, by the time they present for medical care will
have HTN, abnormal kidney function and normal serologic markers. As such, these individuals tend to
be characterized as having CKD caused by HTN rather than HTN caused by CKD.
There are a number of additional causes of CKD that are worth discussing because although
they are not preventable, early detection and treatment can significantly reduce the morbidity
associated with such diseases. Autosomal dominant polycystic kidney disease (ADPKD) affects 1
in 500 (approximately 600,000 in the U.S.) and contributes to approximately 10% of advanced CKD
cases. Polycystic kidney disease individuals develop HTN from the same mechanisms as described
above. In addition, HTN may be further exacerbated by the fact that ADPKD individuals with advanced
CKD tend to have less anemia than non-ADPKD individuals. People affected with ADPKD may
also have HTN from essential HTN or obesity, just like the general population. There are additional
causes of CKD (Table 1) that can directly or indirectly contribute to HTN that should be kept in mind in
assessing individuals with HTN.
Chronic kidney disease is important not just because of the risk for HTN and ESRD, but
also because of the increased risk for cardiovascular (CV) events. 5-7 Individuals with CKD have a
significantly increased risk for CV mortality, starting with relatively small decrements in overall renal
function. 8-10 Hypertension accelerates and further exacerbates this situation. As expected, in the
individual who has the not uncommon combination of CKD, HTN and DM is at extraordinarily high risk
of CV death. Treatment of individuals with CKD is essential to effect what are certainly preventable
excess deaths in this population. Numerous studies demonstrate that control of blood pressure can
slow progression of CKD, particularly in patients with significant proteinuria at the onset of therapy.
Further, and perhaps more importantly, HTN and CKD control can decrease CV events and death.
An analysis of the Fourth National Health and Nutrition Examination Survey (NHANES IV)
reveals that only 37% of subjects had blood pressures controlled to a goal of < 130/< 80 mmHg. 11
The major issue was inadequate control of systolic blood pressures. African Americans were more
than twice as likely and the elderly almost five times more likely to have uncontrolled blood pressures
42 Hypertension Core Curriculum