Mild liver dysfunction in Klinefelter syndrome is associated with abdominal obesity and elevated lipids but not testosterone treatment.

Context: Klinefelter syndrome (KS) is associated with hypergonadotropic hypogonadism, which contributes to characteristic phenotypical manifestations including metabolic alterations. Extensive research has demonstrated important associations between androgens and liver function.

Objectives: Investigation of the association between metabolic parameters, sex hormones and liver function in males with KS, both treated (T-KS) and untreated (U-KS) and healthy control males.

Methods: A total of 65 KS males were recruited, of which 32 received testosterone replacement therapy (TRT). Also, 69 healthy controls were recruited. We used alanine aminotransferase (ALAT), alkaline phosphatase and PP (prothrombin-proconvertin time ratio) as the main liver markers. Multivariable regression was performed within the three groups. All statistics were calculated using STATA. Principal component analysis was utilized to demonstrate the interconnected patterns among all measured biomarkers, and to elucidate how the different groups were linked to these patterns.

Results: Higher levels of main liver markers were observed in U-KS compared to controls, with no significant differences between U-KS and T-KS. T-KS had lower abdominal fat, total cholesterol, and LDL cholesterol than U-KS. Using multivariable models, variation in ALAT in U-KS was explained by HOMA2%S; in T-KS by BMI and SHBG; and in controls by hip circumference and estradiol. We found no multivariable models explaining variation in PP in U-KS; in T-KS, PP was explained by BMI and LDL cholesterol, and in controls by total cholesterol. Using principal component analysis U-KS was positively associated to D1 (an obese profile, which also included ALAT) and controls negatively associated with D1 (non-obese profile).

Conclusion: KS males have mild liver dysfunction reflected by a significant increase in the main liver markers and decrease in albumin. The presented data underscore a primary role of metabolic conditions including obesity, insulin resistance and unfavourable lipid profile, in the elevated liver function markers seen in males with KS. Whether TRT can improve liver function in KS warrants further studies. Our findings, highlight that an evaluation of the liver function should be part of the clinical care in males with KS.