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Patients with non-alcoholic fatty liver disease (NAFLD) also had low potassium levels, researchers in China found.

In a population-based, cross-sectional study, patients with NAFLD had significantly lower serum potassium levels than those who did not have the liver condition (4.09 mM versus 4.14 mM, P<0.0001), Guang Ning, MD, of Shanghai Jiao-Tong University School of Medicine, and colleagues reported online in Clinical Endocrinology.

NAFLD has become an increasing burden on the healthcare system in recent years, so researchers have been interested in identifying risk factors for the condition, particularly with regard to environmental exposures, they noted in their introduction.

Some studies have shown that lack of potassium -- needed for normal cellular function and metabolic balance -- may contribute to various metabolic disorders, including insulin resistance, which may ultimately increase the risk of NAFLD.

To more closely assess the relationship between serum potassium and NAFLD, the researchers enrolled 8,592 Chinese patients -- 2,663 men and 5,929 women -- in their study. Three out of 10 patients in the overall cohort (30.3%) had NAFLD, with the prevalence gradually decreasing across increasing serum potassium quartiles.

Not only did those with NAFLD have significantly lower serum potassium levels than those without, but the prevalence of NAFLD in patients with hypokalemia was significantly higher than that seen in patients with normal serum potassium (40.5% versus 29.6%, P<0.0001).

Patients with lower serum potassium levels also had a larger waist circumference and more severe insulin resistance, and these associations held in multivariate linear regression analyses, they reported.

Compared with patients in the highest quartile of serum potassium, those in the lowest quartile had a higher risk of:

• NAFLD (OR 1.33, 95% CI 1.11-1.60)
• Insulin resistance (OR 1.81, 95% CI 1.49-2.19)
• Central obesity (OR 1.58, 95% CI 1.30-1.93)

In adjusted subgroup analyses, the researchers also found a significant relationship between serum potassium levels and the following factors:

• Female sex (OR 1.11, 95% CI 1.03-1.19, P=0.006)
• Younger age (OR 1.13, 95% CI 1.04-1.23, P=0.005)
• Central obesity (OR 1.16, 95% CI 1.07-1.25, P=0.0001)
• Insulin resistance (OR 1.17, 95% CI 1.06-1.30, P=0.003)

One potential mechanism linking low potassium levels with NAFLD is insulin resistance, the researchers said. Potassium depletion could cause low nitric oxide levels and endothelial dysfunction, they noted, which could ultimately lead to insulin resistance, as well as hypertriglyceridemia and glucose intolerance.

The study was limited, however, because NAFLD was diagnosed via ultrasound, instead of the gold standard of liver biopsy, and by the fact that the researchers did not assess dietary potassium intake.

Still, the researchers concluded that decreased serum potassium is associated with the prevalence of NAFLD and that insulin resistance and central obesity may play an important role in this association.

They called for further observational studies and clinical trials to determine whether correcting potassium deficiency can effectively reduce the incidence of NAFLD.

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