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CAP accurately measures severe alcoholic steatosis

Controlled attenuation parameter accurately diagnosed severe alcoholic steatosis, according to recently published data. Further, controlled attenuation parameter rapidly declined after abstinence from alcohol in non-obese patients.

“Harmful drinking is often accompanied by similar unfavourable health behaviours such as overeating, smoking and a sedentary lifestyle,” Maja Thiele, PhD, from the Odense University Hospital of Southern Denmark, and colleagues wrote. “Components of the metabolic syndrome (MetS) are common in alcoholic patients, where they may aggravate steatosis and act in synergy with alcohol to progress fibrosis. Consequently, reliable noninvasive tools to diagnose and monitor hepatic steatosis in patients with alcoholic liver disease (ALD) are needed.”

To determine the diagnostic value of CAP for evaluation of hepatic steatosis, the researchers enrolled 269 patients with history of heavy alcohol use into a diagnostic cohort and 293 patients admitted for detoxification for severe alcohol consumption into the detoxification cohort.

In the diagnostic cohort, CAP demonstrated fair diagnostic accuracy for any steatosis grade (area under the receiver operating characteristic curve [AUC] = 0.77; 95% CI, 0.71-0.83) and moderate steatosis (AUC = 0.78; 95% CI, 0.72-0.83) and better accuracy for grade 3 severe steatosis (AUC = 0.82; 95% CI, 0.75-0.88). The researchers did not observe any significant differences in subgroup analyses of active drinkers compared with patients who were abstinent prior to enrollment, country of origin, presence of bright liver echo pattern or fibrosis stage.

CAP measurements higher than 290 dB/m ruled in any steatosis with a specificity of 88% and a positive predictive value of 92%. CAP less than 280 dB/m ruled out severe steatosis with a sensitivity of 94% and a negative predictive value of 99%. CAP less than 220 dB/m ruled out any steatosis with 90% sensitivity, although the negative predictive value (NPV) was only 62%. CAP higher than 339 dB/m ruled in severe steatosis.

In the diagnostic cohort, CAP was significantly lower in the 84 patients who abstained from alcohol more than 4 weeks prior to enrollment compared with active drinkers (253 vs. 283 dB/m; P < .001). However, the researchers saw no significant difference in the accuracy of CAP to diagnose steatosis in subgroup analyses of abstainers vs. drinkers.

Histological liver steatosis score (r = 28.4; 95% CI, 22.8-34), BMI (r = 4.2; 95% CI, 3-5.3) and age (r = 0.8; 95% CI, 0.3-1.3) independently predicted CAP.

In the detoxification cohort, CAP declined in 76% of patients during a median 6.3 days of hospital stay (range, 3-26 days) from a mean of 293 dB/m to 261 dB/m (P < .001). Seventy-two patients showed stable or increased CAP measurements.

BMI (r = 3.7; 95% CI, 2.41-4.99) and gamma-glutamyltransferase (r = 0.02; 95% CI, 0.01-0.029) independently predicted CAP at admission.

CAP was higher among patients with metabolic syndrome in both the diagnostic cohort (302 vs. 262 dB/m; P < .001) and the detoxification cohort (306 vs. 284 dB/m; P < .001) and among patients with obesity — or BMI higher than 30 kg/m² — in the diagnostic cohort (311 vs. 261 dB/m; P < .001) and detoxification cohort (318 vs. 290 dB/m; P = .003). During detoxification, CAP decreased equally in patients with and without metabolic syndrome, except among patients with BMI higher than 30 kg/m².

“Our multicenter study identifies CAP as an accurate bedside tool to detect and follow up the grade of steatosis in alcoholic fatty liver disease, and stresses the synergy between harmful drinking and poor metabolic health on the development of liver steatosis,” the researchers concluded. “Superior time efficiency, cost and availability places CAP as the most convenient and reliable non-invasive marker of steatosis in patients with alcoholic liver disease. Finally, the fact that CAP does not decrease during alcohol detoxification in obese patients highlights the key role of fat metabolism in patients with ALD.” – by Talitha Bennett

Disclosure: The authors report relevant financial disclosures.