Unexplained CK elevations in patients with nonalcoholic steatohepatitis

Gender-differences in the associations between circulating creatine kinase, blood pressure, body mass and non-alcoholic fatty liver disease in asymptomatic asians

BACKGROUND

Creatine kinase (CK) is a pivotal regulatory enzyme in energy metabolism linked to both blood pressure and cardio-metabolic components. However, data is lacking in a large population of asymptomatic Asians.

METHODS AND RESULTS

Cardio-metabolic assessment including anthropometric measures and non-alcoholic fatty liver disease (NAFLD) were evaluated by abdominal echo in 4,562 consecutive subjects who underwent an annual health survey. Serum CK levels were related to blood pressure components [systolic blood pressure (SBP), diastolic blood pressure (DBP), and pulse pressure (PP)], anthropometric measures, and excessive adiposity in liver as indicated by NAFLD. Circulating CK levels ranged from 4 to 1842 IU/L (mean [SE]: 108.7 [1.1] IU/L) in the study population which consisted of 2522 males (mean age: 48.7 ± 11.2) and 2040 females (mean age: 49.4±11.5). In general, male subjects presented with higher circulating CK levels than females (mean ± SE: 127.3 ± 1.5 vs. 85.5 ± 1.3 IU/L, respectively, p < .001). Gender-differences in circulating CK levels were also observed with increasing age, which showed a more pronounced positive relationship with age in female subjects (gender interaction: p < .05). Furthermore, an elevated circulating CK level was independently associated with higher blood pressure, waist circumference and fat mass (FM), greater body mass index (BMI), increased lower estimated glomerular filtration rate (eGFR) and presence of NAFLD in multivariate analysis (all p < .05), with CK elevation more pronounced with greater BMI and FM in males compared with females (sex interaction: p < .05).

CONCLUSION

In a large asymptomatic Asian population, circulating CK levels were increased with more advanced age, higher blood pressure, and greater body mass with gender differences. Our findings may be useful in interpreting elevated CK from subjects free of ongoing myocardial damage.

Fatty liver and the metabolic syndrome

PURPOSE OF REVIEW

Nonalcoholic fatty liver disease and its subset nonalcoholic steatohepatitis represent the liver manifestations of insulin resistance. This review briefly summarizes advances in our understanding of the pathogenesis of nonalcoholic fatty liver disease and its prevalence, natural history and treatment.

RECENT FINDINGS

The recognition of the role the renin-angiotensin system in promoting insulin resistance is worth noting because of available drugs. Endoplasmic reticulum stress has also become a recent target of investigation because endoplasmic reticulum stress is common in obesity, diabetes and various forms of liver disease including nonalcoholic fatty liver disease. Endoplasmic reticulum stress may be responsible for activation of c-Jun kinase, a process that may cause the hepatocellular injury in nonalcoholic steatohepatitis. Progress has also been made in estimating the prevalence of nonalcoholic fatty liver disease in adults and children. Patients enrolled in the Dallas Heart Study were found to have a 33% prevalence of nonalcoholic fatty liver disease and children dying of accidental deaths in San Diego were found to have a 13% prevalence of nonalcoholic fatty liver disease. Because about 10% of people with nonalcoholic fatty liver disease are at risk for progressive fibrosis, the burden of this disease is now quite substantial.

SUMMARY

Incremental progress in understanding nonalcoholic fatty liver disease and nonalcoholic steatohepatitis promises to lead to new therapeutic options for this common disease.