CF and male health: Sexual and reproductive health, hypogonadism, and fertility.

Over 30,000 people in the United States are diagnosed with cystic fibrosis (CF), and over 50% of those with CF are male. Men with CF face specific and sometimes difficult sexual and reproductive health (SRH) issues, including infertility and hypogonadism. Male infertility affects over 95% of men with CF, with obstructive azoospermia resulting from congenital bilateral absence of the vas deferens being the primary cause of infertility. SRH education for males with CF represents an important opportunity for clinical improvement, as the majority of men with CF know that their disease impacts their fertility, however the depth of this understanding varies significantly. Hypogonadism is a clinical syndrome that affects men with low testosterone level, a common finding among men with CF that has clinical implications and can significantly affect quality of life. Better understanding of SRH attitudes, the prevalence of hypogonadism, and management of infertility in men with CF should remain future research priorities.

Body composition in individuals with cystic fibrosis.

Because nutritional status is intimately linked with pulmonary function and survival, nutrition has been at the mainstay of cystic fibrosis (CF) care. Body Mass Index (BMI) is traditionally used to define nutritional status because of the ease with which it can be calculated, but it has a number of limitations including its inability to differentiate fat mass (FM) from lean body mass (LBM), the latter thought to confer health advantage. A number of tools are available to quantify body composition including dual-energy x-ray absorptiometry (DXA), bioelectrical impedance, MRI, CT, air displacement plethysmography, and stable isotopes, and these have been used to varying degrees in studies of CF. In CF, LBM tends to be lower for a given BMI, particularly at lower BMI. In adults, lower fat-free mass (FFM) correlates with greater CF disease severity, lower pulmonary function and higher inflammatory markers. FFM is also positively associated with greater bone mineral density, while greater FM is associated with greater loss of lumbar spine bone mineral density over 2 years. In youth, LBM is positively associated with pulmonary function. The predictive value of body composition for functional and clinical outcomes and the role of improving LBM on these outcomes remain undefined. With improvements in BMI accompanying highly-effective modulator therapy, closer evaluations of body composition may inform risk for more traditional, non-CF adult outcomes in CF.