Both chronic kidney disease and nocturnal blood pressure associate with strokes in the elderly

Circadian regulation of renal function

The kidneys regulate many vital functions that require precise control throughout the day. These functions, such as maintaining sodium balance or regulating arterial pressure, rely on an intrinsic clock mechanism that was commonly believed to be controlled by the central nervous system. Mounting evidence in recent years has unveiled previously underappreciated depth of influence by circadian rhythms and clock genes on renal function, at the molecular and physiological level, independent of other external factors. The impact of circadian rhythms in the kidney also affects individuals from a clinical standpoint, as the loss of rhythmic activity or clock gene expression have been documented in various cardiovascular diseases. Fortunately, the prognostic value of examining circadian rhythms may prove useful in determining the progression of a kidney-related disease, and chronotherapy is a clinical intervention that requires consideration of circadian and diurnal rhythms in the kidney. In this review, we discuss evidence of circadian regulation in the kidney from basic and clinical research in order to provide a foundation on which a great deal of future research is needed to expand our understanding of circadian relevant biology.

Integrating Out-of-Office Blood Pressure in the Diagnosis and Management of Hypertension

Guidelines for the diagnosis and monitoring of hypertension were historically based on in-office blood pressure measurements. However, the US Preventive Services Task Force recently expanded their recommendations on screening for hypertension to include out-of-office blood pressure measurements to confirm the diagnosis of hypertension. Out-of-office blood pressure monitoring modalities, including ambulatory blood pressure monitoring and home blood pressure monitoring, are important tools in distinguishing between normotension, masked hypertension, white-coat hypertension, and sustained (including uncontrolled or drug-resistant) hypertension. Compared to in-office readings, out-of-office blood pressures are a greater predictor of renal and cardiac morbidity and mortality. There are multiple barriers to the implementation of out-of-office blood pressure monitoring which need to be overcome in order to promote more widespread use of these modalities.

Treatment of hypertension in children with chronic kidney disease

Hypertension (HTN) is increasingly recognized as a common feature of pediatric chronic kidney disease (CKD). A growing body of evidence demonstrates that HTN is both underdiagnosed and undertreated in this population. The consequences of untreated HTN include adverse effects on CKD progression, markers of cardiovascular morbidity, and neurocognitive functioning. Consensus guidelines issued over the past decade have incorporated recent research on the consequences of HTN in recommendations for the diagnosis and treatment of HTN in pediatric CKD and include lower BP targets. Agents which target the renin-angiotensin-aldosterone system (RAAS) should be considered first-line therapy in CKD-associated HTN in children, though multiple medications may be required to achieve sufficient BP control.

Racial impact of diurnal variations in blood pressure on cardiovascular events in chronic kidney disease

Ambulatory blood pressure parameters, nocturnal dipping and morning surge, are associated with cardiovascular outcomes in several populations. While significant variation exists between racial groups in ambulatory blood pressure measurements and the incidence of cardiovascular disease, the effect of race on the associations of dipping and morning surge with cardiovascular outcomes is unknown. In a prospective analysis of 197 African American and 197 Japanese individuals with non-diabetic chronic kidney disease matched by age and renal function, we analyzed the associations of dipping and morning surge with cardiovascular events for both races and assessed whether these relations differed by race. Higher sleep-trough morning surge was independently associated with cardiovascular events in Japanese (hazard ratio, 1.93 per 10 mm Hg; 95% confidence interval, 1.20-3.10) but not in African American participants, with race an effect modifier (P-value <.01). Dipping was not associated with cardiovascular events in either racial group. In individuals with chronic kidney disease, the association between morning surge and cardiovascular events appears to be dependent upon race, with higher morning surge a risk factors in Japanese but not in African Americans.