Healthy Weight, but Expanding Waist Boosts Fatty Liver Risk

Kate Johnson

April 22, 2016

BARCELONA, Spain — An expanding waistline might be an indicator of increased risk for nonalcoholic fatty liver disease, even if body mass index is in the normal range, researchers reported here at the International Liver Congress 2016.

"Our suggestion is that all patients need their waist circumference measured, even if they have a normal body mass index. If the waistline has increased and other metabolic features, such as diabetes, hypertension, dyslipidemia, and insulin resistance, are present, they need to be screened for nonalcoholic fatty liver disease," said Rosa Lombardi, MD, from the University of Milan.

The findings add to evidence of the existence of "lean" fatty liver disease, which might be associated with a worse metabolic and liver profile than the more widely recognized obesity-related fatty liver disease, she told Medscape Medical News.

"Because our sample was small, these data cannot be considered conclusive, but there is a trend showing that lean fatty liver disease is associated with a higher prevalence of metabolic syndrome [P = .04] and severe liver fibrosis [P = .05], compared with obese fatty liver disease," Dr Lombardi reported.

The retrospective analysis involved 334 patients with biopsy-proven nonalcoholic fatty liver disease; 61 were normal weight (BMI < 25 kg/m²) and the rest were overweight.

In the normal-weight patients, indications for liver biopsy were persistently altered liver function tests, hyperferritinemia, and/or a long history of steatosis, especially if associated with diabetes.

Investigators used carotid intima media thickness and plaque on ultrasound to assess vascular damage, and performed liver biopsy to evaluate fibrosis.

At baseline, waist circumference was larger in overweight than in normal-weight patients (104.1 vs 89.9 cm; P < .0001).

Table. Metabolic Features at Baseline

Metabolic Feature Overweight Patients Normal-Weight Patients P Value
Hypertension 42% 21% .001
Diabetes 25% 6% .0006
Homeostatic model assessment insulin resistance 4.5 2.8 <.0001
Metabolic syndrome 43% 13% <.0001
Carotid intima media thickness 0.84 mm 0.72 mm .0009
Plaque 33% 13% .007
Nonalcoholic steatohepatitis 63% 36% .0001
Grade 2 liver fibrosis or higher 38% 20% .02

Of particular interest is the fact that among the 61 patients with a BMI in the normal range, nearly 36% had nonalcoholic steatohepatitis and 20% had significant (grade 2 or higher) fibrosis, Dr Lombardi pointed out.

But regardless of BMI, those with larger waistlines had worse metabolic, vascular, and liver profiles than those with smaller waistlines.

Although waist circumference and BMI are often correlated, 24 patients with a BMI in the normal range had an increased waist circumference — greater than 80 cm for women and 94 cm for men.

In fact, waist circumference is a better predictor than BMI of diabetes (odds ratio [OR], 4.5 vs 2.4) and fibrosis (OR, 2.6 vs 1.5), she reported.

"This study has proven to us that the severity of nonalcoholic fatty liver disease is not necessarily linked to how obese an individual is, but instead how much fat build-up they have around the waist," Frank Tacke, MD, PhD, from University Hospital Aachen in Germany, who is a member of the EASL Governing Board, said in a news release.

"The results have highlighted the need for additional research into why analyzing someone's waist, and not just their weight, is important in detecting individuals at risk for complications associated with this disease," Dr Tacke pointed out.

Dr Lomardi and Dr Tacke have disclosed no relevant financial relationships.

International Liver Congress (ILC) 2016: Abstract PS110. Presented April 16, 2016.


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