Dr. Ron’s Research Review – November 13, 2013

© 2013

This week’s research review focuses on cholesterol and statins.

A recent article published in the Journal of Stroke and Cerebrovascular Diseases is entitled "High cholesterol levels are associated with improved long-term survival after acute ischemic stroke." (Markaki, Nilsson et al. 2013)

Total cholesterol of 4.6 mmol/L or more was defined as high.

Three-month, 1-year, and 5-year survival rates were 100%, 98%, and 84%, respectively, in high cholesterol patients, compared with 92%, 87%, and 57% in low cholesterol group (P = .0001 with the log-rank test). Mortality risk was increased for patients with low cholesterol (hazard ratio: 1.97; 95% confidence interval [CI]: 1.05-3.69), after adjustment for age and admission National Institutes of Health Stroke Scale score. After further adjustment for angina and admission BP, the effect of cholesterol on mortality risk was still obvious, yet attenuated (hazard ratio: 1.87; 95% CI: .94-3.32).

Survival Rates

high TC

Low TC

Three-month

100%

92%

1-year

98%

87%

5-year

84%

57%

Randomised controlled trials have shown an excellent preventive effect of statins on ischemic heart disease. A recent study, however, found that statins had no correlation to the incidence or mortality of acute myocardial infarction. (Nilsson, Molstad et al. 2011)

Dr. Ron


Articles

High Cholesterol Levels Are Associated with Improved Long-term Survival after Acute Ischemic Stroke

         (Markaki, Nilsson et al. 2013) Download

BACKGROUND: Prior statin treatment and high admission cholesterol have been associated with favorable outcome after ischemic stroke (IS), a paradox not completely explained. The aim of this study was to investigate the effect of admission cholesterol levels and the impact of statin treatment on short- and long-term survival after IS. METHODS: Consecutive patients admitted in 2006 and 2010 were included in the study. Total cholesterol of 4.6 mmol/L or more was defined as high. Logistic regression analysis was performed to assess predictors of 1-month mortality, and Cox proportional hazard regression analysis was applied to investigate predictors of long-term mortality. RESULTS: Of 190 patients included in the final analysis, 21 (11%) died within 1 month and 61 (32%) died during 7 years of observation. Low cholesterol was associated with older age, lower blood pressure (BP), presence of angina, and higher risk of death. Three-month, 1-year, and 5-year survival rates were 100%, 98%, and 84%, respectively, in high cholesterol patients, compared with 92%, 87%, and 57% in low cholesterol group (P = .0001 with the log-rank test). Mortality risk was increased for patients with low cholesterol (hazard ratio: 1.97; 95% confidence interval [CI]: 1.05-3.69), after adjustment for age and admission National Institutes of Health Stroke Scale score. After further adjustment for angina and admission BP, the effect of cholesterol on mortality risk was still obvious, yet attenuated (hazard ratio: 1.87; 95% CI: .94-3.32). CONCLUSIONS: High admission cholesterol may be associated with increased long-term survival after IS. Future studies on the temporal profile of cholesterol levels and stroke outcome would be of interest.


No connection between the level of exposition to statins in the population and the incidence/mortality of acute myocardial infarction: an ecological study based on Sweden's municipalities

         (Nilsson, Molstad et al. 2011) Download

BACKGROUND: Randomised controlled trials have shown an excellent preventive effect of statins on ischemic heart disease. Our objective was to investigate if a relation can be detected between acute myocardial infarction- (AMI) mortality or incidence and statin utilisation, for men and women in different age-groups on a population basis. RESULTS: The utilisation rate of statins increased almost three times for both men and women between 1998 and 2002. During 1998-2000 the incidence of AMI decreased clearly for men but only slightly for women. Mortality decreased from 1998 to 2002. The change in statin utilisation from 1998 to 2000 showed no correlation to the change in AMI mortality from 2000 to 2002. Statin utilisation and AMI- incidence or mortality showed no correlations when adjusting for socio-economic deprivation, antidiabetic drugs and geographic coordinates. CONCLUSIONS: Despite a widespread and increasing utilisation of statins, no correlation to the incidence or mortality of AMI could be detected. Other factors than increased statin treatment should be analysed especially when discussing the allocation of public resources.

References

Markaki, I., U. Nilsson, et al. (2013). "High Cholesterol Levels Are Associated with Improved Long-term Survival after Acute Ischemic Stroke." J Stroke Cerebrovasc Dis. [PMID: 24103674]

Nilsson, S., S. Molstad, et al. (2011). "No connection between the level of exposition to statins in the population and the incidence/mortality of acute myocardial infarction: an ecological study based on Sweden's municipalities." J Negat Results Biomed 10: 6. [PMID: 21609438]