Low Potassium Linked with Liver Disease

By Kristina Fiore, Staff Writer, MedPage Today

Published: May 21, 2013

Reviewed by F. Perry Wilson, MD, MSCE; Instructor of Medicine, Perelman School of Medicine at the University of Pennsylvania

Action Points

• Note that this cross-sectional study demonstrated an association between non-alcoholic fatty liver disease and lower potassium levels in a Chinese population.
• Be aware that the mean potassium difference between those with and without NAFLD was extremely small, made significant due to the large sample size.

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.

The study was supported by the Ministry of Health of China, the National Natural Science Foundation of China, and the Shanghai New Excellent Youth Program.

The researchers reported no conflicts of interest.

Primary source: Clinical Endocrinology
Source reference:
Sun K, et al "Low serum potassium level is associated with non-alcoholic fatty liver disease and its related metabolic disorders" Clinical Endocrinol 2013; DOI: 10.1111/cen.12168.

Source