Prevalence of Fabry Disease in Korean Men with Left Ventricular Hypertrophy

BACKGROUND

Fabry disease is an X-linked recessive disorder caused by deficiency of the lysosomal enzyme α-galactosidase A (α-Gal A). Previous studies identified many cases of Fabry disease among men with left ventricular hypertrophy (LVH). The purpose of this study was to define the frequency of Fabry disease among Korean men with LVH.

METHODS

In this national prospective multicenter study, we screened Fabry disease in men with LVH on echocardiography. The criterion for LVH diagnosis was a maximum LV wall thickness 13 mm or greater. We screened 988 men with LVH for plasma α-Gal A activity. In patients with low α-Gal A activity (< 3 nmol/hr/mL), we searched for mutations in the α-galactosidase gene.

RESULTS

In seven men, α-Gal A activity was low. Three had previously identified mutations; Gly328Arg, Arg301Gln, and His46Arg. Two unrelated men had the E66Q variant associated with functional polymorphism. In two patients, we did not detect GLA mutations, although α-Gal A activity was low on repeated assessment.

CONCLUSION

We identified three patients (0.3%) with Fabry disease among unselected Korean men with LVH. Although the prevalence of Fabry disease was low in our study, early treatment of Fabry disease can result in a good prognosis. Therefore, in men with unexplained LVH, differential diagnosis of Fabry disease should be considered.

Seasonal Variations and Correlations between Vitamin D and Total Testosterone Levels

Background

Some studies have provided evidence for a possible association between vitamin D and testosterone levels; however, the evidence from studies in Koreans is inconsistent. In addition, insufficient evidence is available to support an association between seasonal variations in vitamin D and testosterone levels in Koreans. Therefore, we aimed to investigate the association between vitamin D and testosterone levels, and between seasonal variations in these levels in Korean men.

Methods

This cross-sectional study included 1,559 men, aged 25–86 years, who underwent a medical examination. We measured serum 25-hydroxyvitamin D (25[OH]D) and total testosterone levels, and compared other laboratory test results and patient lifestyle characteristics. On the basis of sample collection time, we categorized patients into four seasons, and analyzed seasonal variability in 25(OH)D and total testosterone levels.

Results

The average participant age (±standard deviation) was 53.3±8.8 years, and the average serum 25(OH)D and total testosterone levels were 15.9±7.0 ng/mL and 5.1±1.6 ng/mL, respectively. In the analysis of variance (ANOVA) model, no significant association was found between 25(OH)D and testosterone levels (P=0.51). ANOVA of the average 25(OH)D levels in season-based groups revealed significant seasonal variations in 25(OH)D levels (P-value for trend <0.001). No significant association was found between seasonal variations in total testosterone levels (P=0.06). However, after adjustment for confounding variables, total testosterone and 25(OH)D showed significant seasonal variability (P=0.007 and P<0.001, respectively).

Conclusion

We found no significant correlation between serum 25(OH)D and total testosterone levels in Korean men. Moreover, serum 25(OH)D and total testosterone levels showed significant seasonal variations.