Statins in chronic kidney disease
The inclusion of statins in managing chronic kidney disease (CKD) may help reduce patient mortality from stroke and possibly other cardiovascular events, according to an expert at the 7th Malaysian Endocrine and Metabolic Society (MEMS) Annual Congress.
A systematic review of existing small-scale studies on the efficacy and safety of high-intensity therapy with rosuvastatin (20 to 40 mg) or atorvastatin (40 to 80 mg) found the drugs significantly reduced risk of stroke in patients with CKD by around 31 percent, although without significant effect on myocardial infarction, heart failure and renal protection. [BMJ Open 2015;doi:10.1136/bmjopen-2014-006886]
According to Professor Dr. Abdul Halim Abdul Gafor, consultant nephrologist at Universiti Kebangsaan Malaysia Medical Center, CKD and cardiovascular disease (CVD) share ‘traditional’ risk factors such as diabetes, hypertension and dyslipidaemia, and ‘non-traditional’ risk factors such as proteinuria, uremia, anaemia, hyperparathyroidism and high calcium-phosphate levels. In addition, dialysis often adds to CVD risk due to malnutrition and low blood pressure from the treatment.
Speaking at the recent 7th Annual Congress of the Malaysian Endocrine and Metabolic Society, Abdul Halim highlighted that between 14 to 18 percent of Malaysian patients on peritoneal dialysis (PD) and 12 to 13 percent on haemodialysis (HD) die annually, based on statistics from the 22nd report of the Malaysian Dialysis and Transplant Registry (MDTR). Of these, cardiovascular events were the most frequently recorded cause—accounting for 34 to 37 percent of deaths between 2010 and 2015.
“Another 16 to 18 percent die at home, and we assume that they may also have died due to CVD. So if you add both the (known) CVD and the die-at-home cases, you have about 50 percent of dialysis patients dying from CVD,” said Abdul Halim. “Many of these deaths are patients with mild CKD— having eGFR below 60 or below 90, and with proteinuria.”
Population studies involving statin use in dialysis patients in general (eg, 4D, AURORA, SHARP, and ALERT) to date have shown mixed results in reducing CV events; the SHARP trials reported a significant reduction of myocardial infarction by 17 percent, while the 4D and AURORA trials showed no significant improvement of risk for any CV events measured. Therefore, the interactions between statins, effects of dialysis, and existing CKD are not yet fully clear, according to Abdul Halim, as there have been no large-scale studies with specific focus on those.
In general, based on existing data, Abdul Halim concluded that lipid lowering seemed to reduce risk of stroke and myocardial infarction in patients with CKD stages 2 to 4. However, there remains a lack of conclusive evidence that statins can actually retard renal disease progression. Furthermore, he cautioned that the adverse effects of statins applied similarly to CKD and non-CKD patients; low LDL levels coupled with dialysis could also increase mortality, while some statins such as rosuvastatin have been demonstrated to increase proteinuria levels.
“What is important is monitoring and risk stratifying our patients,” said Abdul Halim. “For CKD patients who are not on dialysis, consider starting them on statins. For thin, malnourished CKD patients, we know that cholesterol is not their main problem.”
For patients with moderate to severe CKD, he recommended a target LDL cholesterol of 2.6 mmol/L rather than the general target of 1.8 given by the European Society of Cardiology in 2011.
According to the 2011 National Health and Morbidity Survey, CKD (defined as persistent albuminuria and/or eGFR below 90) was found to affect 9.07 percent of adult West Malaysian respondents; however, only 4 percent of CKD patients identified were aware of their condition.