Creatine kinase in the U.S. population

Abstract

Background:Creatine kinase (CK) values are a critical part of the workup of suspected myopathies and are often assessed in patients that develop myalgia on statin therapy. CK elevations may influence the initiation and cessation of statin treatment, and incidentally discovered CK elevation may lead to further testing. A number of factors influence CK levels in healthy patients, but current reference ranges do not incorporate important influencers of CK such as race. Objectives of this study were to evaluate clinical factors associated with CK among healthy individuals and to develop practical reference ranges for important subgroups to improve test interpretation.Methods:CK was evaluated in nonpregnant participants ≥20 years old from the cross-sectional National Health and Nutrition Examination Survey (NHANES) 2011–2014. Linear and logistic regression stratified by sex identified clinical factors associated with CK levels. Adjustment for anthropomorphic measures assessed whether age and race-ethnicity differences in CK were explained by differences in body composition. The 95th and 97.5th percentiles of CK in sex/race-ethnicity subgroups were calculated, excluding patients with recent strenuous exercise.Results:A total of 10,096 nonpregnant adults were studied. Black race was strongly associated with CK. The odds ratio of having an abnormal CK for black women was 5.08 (95% CI 3.65–7.08) and for black men was 8.39 (95% CI 6.11–11.52). CK was substantially lower in older men. Differences in CK by age but not race-ethnicity were largely explained by body composition. Women with low body mass index were less likely to have an elevated CK, and overweight or obese men had an almost 2-fold greater odds of having an elevated CK. The 97.5th percentile of CK was 382 (95% CI 295–469) in white men, 1001 (95% CI 718–1284) in black men, 295 (95% CI 216–374) in white women, and 487 (95% CI 310–664) in black women.Conclusion:CK is substantially higher in men and in black patients. Differences in body size and composition are also important but do not explain racial differences in CK. The 95th and 97.5th percentiles in sex and race-ethnicity subgroups provide a practical guide for clinicians interpreting CK values.

Effects of age and gender on reference levels of biomarkers comprising the pediatric Renal Activity Index for Lupus Nephritis (p-RAIL)

“…It would be important to note that not only does creatinine have an intrinsic relationship with age, it also displays a significant relationship with gender. It is well known that creatinine is higher in males, especially after puberty, than females [ 40 , 41 ]. As a result, creatinine correction would amplify the difference between males and females in terms of biomarker levels.…”

Creatine kinase is associated with reduced inflammation in a general population: The Tromsø study

“…CK is associated with body mass index (BMI) in population-based studies [ 11 , 12 ] and in a case-control study primarily designed to investigate the relationship between CK and blood pressure [ 13 ]. Inflammatory markers in obese women with reduced muscle mass and increased fat mass (sarcopenic obesity) were associated with higher CK [ 14 ].…”

Creatine Kinase and Blood Pressure: A Systematic Review

“…The study flow is depicted in Figure 2 and the included studies are in Table 1 [6,7,11,12,13,14,15,16,17,18,19]. We retrieved 135 reports from electronic databases and included 7 reports from 6 studies [6,7,11,15,16,17,19].…”