The association of dyslipidemia with chronic lymphocytic leukemia: a population-based study

Background — Metabolic syndrome (MetS) is a risk factor for development of cancer. Because aberrant lipid metabolism is a pathogenic feature of chronic lymphocytic leukemia (CLL), our objective was to determine if CLL patients have a higher prevalence of MetS preceding diagnosis and to determine the impact of lipid-lowering medications on survival.

Methods — We conducted a population-based case-control study in Ontario, Canada, using administrative databases of adults age 66 years and older to compare the prevalence of MetS preceding CLL with age- and sex-matched control subjects. Logistic regression was used to study the association between MetS and its components to CLL. The Kaplan-Meier method and Cox Regression were used to investigate survival. All statistical tests were two-sided.

Results — We identified 2124 persons with CLL and 7935 control subjects from January 1, 2000, to December 31, 2005, with follow-up until March 31, 2014, three years from the date of last contact with the healthcare system, or death. The mean age was 75.6 years, 20.2% had diabetes, 35.8% had hypertension, and 17.6% had dyslipidemia. In multivariable analysis, dyslipidemia (odds ratio [OR] = 1.26, 95% confidence interval [CI] = 1.11 to 1.44, P < .001) and hypertension (OR = 1.12, 95% CI = 1.01 to 1.25, P = .03) were associated with the development of CLL, whereas MetS and diabetes were not. Lipid-lowering medication was associated with a statistically significant improved survival in patients with CLL (HR = 0.53, 95% CI = 0.47 to 0.61, P < .001).

Conclusions — We demonstrate a higher prevalence of dyslipidemia preceding a diagnosis of CLL compared with control subjects, supporting preclinical data. Lipid-lowering medications appear to confer a survival advantage in CLL. Prospective studies are needed to confirm these results and test their potential as therapeutic applications.