Creatine kinase activity and blood pressure in a normal population: the Tromsø study

OBJECTIVESIn the vast majority of cases the cause for hypertension is not known. On the basis of observations from black and multiethnic populations, it has been hypothesized that a genetically high tissue creatine kinase activity may be an independent factor responsible for primary hypertension. If the relation between creatine kinase and blood pressure is causal, it is reasonable to believe that it will be independent of ethnicity and present in different populations. In this cross-sectional study, we examined whether creatine kinase was associated with blood pressure in a large Caucasian normal population. METHODS AND RESULTSData on creatine kinase and blood pressure were analyzed in a random sample of 12 776 men and women (65% of those eligible), aged 30–87 years from a normal population in the municipality of Tromsø, Norway. We used linear regression to model the association between creatine kinase and blood pressure. Creatine kinase was independently associated with blood pressure. A one unit increase in log CK was associated with a 3.3 (95% CI 1.4–5.2) mmHg increase in systolic blood pressure and a 1.3 (95% CI 0.3–2.3) mmHg increase in diastolic blood pressure, after adjustment for age, sex, body mass index, s-glucose, s-creatinine, physical activity and alcohol consumption. The creatine kinase effect on blood pressure was independent of antihypertensive medication, and no difference in creatine kinase level was found between those with controlled and uncontrolled hypertension (geometric mean 101 vs. 104 IU/l, P = 0.1). CONCLUSIONCreatine kinase was associated with blood pressure in this population.