Socioeconomic trajectories affect mortality in Klinefelter syndrome

Klinefelter syndrome (KS) is associated with male infertility, hypogonadism, and learning disability. Morbidity and mortality are increased and the causes behind remain unknown. Is it the chromosome aberration or is it caused by postulated poorer socioeconomic status?

The aim of the study was to study the socioeconomic profile in KS and the impact of these factors on mortality.

This was a register study using Danish nationwide registries. One thousand forty-nine KS men and 100,824 controls were included. Information concerning cohabitation, fatherhoods, level of education, income, retirement, and death were obtained. Two hundred four KS and 14,725 controls died during the study period. For the socioeconomic parameters, median age at first relevant episode was calculated. Cohabitation, fatherhood, educational level, and retirement were analyzed using Cox regression, and income was analyzed using conditional logistic regression. Both analyses using each case and his matched controls as one stratum.

KS men had significantly fewer partnerships [hazard ratio (HR) 0.66] and entered them later (median age 27.1 vs. 24.6 yr), fewer fatherhoods (HR 0.24),and they occurred later (median age 32.0 vs. 27.0 yr), lower educational level (HR 0.27), and lower income and were retired at an earlier age (43.5 vs. 60.3 yr). Mortality among KS men was significantly increased (HR 1.9), and after adjustment for cohabitation and educational status, mortality was still significantly increased (HR 1.5).

A severely inferior outcome in all investigated socioeconomic parameters compared with the background population was present and mortality was increased and may partially be caused by the poorer socioeconomic status.