Cystic fibrosis related diabetes: Nutrition and growth considerations.

Nutritional considerations are crucial to the optimal management of cystic fibrosis related diabetes (CFRD). The development of abnormal glucose tolerance and CFRD can have negative effects on CF nutritional status. Treatment of CFRD with insulin replacement is essential; however, medical nutrition therapy is important to maintain nutritional status while normalizing blood glucose levels. CF Foundation Nutritional Guidelines are recommended for the nutritional management of CFRD; specifically, the diet should be high in calories, protein, fat, and salt. Carbohydrate intake is not limited, but carbohydrate counting can be used to guide insulin dosing and maintain consistent blood glucose levels. CFTR modulator therapy shows early promise for the improvement of growth and nutritional parameters in CF.

Puberty in cystic fibrosis.

Historically, delayed puberty was considered a common clinical feature of cystic fibrosis (CF). More recent reports have documented normal pubertal progression in the majority of individuals with CF. However, youth with more severe disease are still at risk for delayed puberty. Careful evaluation of pubertal development in children and adolescents with CF is important as pubertal timing impacts linear growth, bone mineral accrual, body image and psychosocial wellbeing, all of which can also be impacted directly by CF. This article reviews the physiology of puberty, timing of puberty in CF, evaluation of pubertal development, and the differential diagnosis, evaluation, and management of delayed and precocious puberty in people with CF.

Hypophosphatemic rickets: lessons from disrupted FGF23 control of phosphorus homeostasis.

Fibroblast growth factor-23 (FGF23) regulates phosphate reabsorption in the kidney and therefore plays an essential role in phosphate balance in humans. There is a host of defects that ultimately lead to excess FGF23 levels and thereby cause renal phosphate wasting and hypophosphatemic rickets. We describe the genetic, pathophysiologic, and clinical aspects of this group of disorders with a focus on X-linked hypophosphatemia (XLH), the best characterized of these abnormalities. We also discuss autosomal dominant hypophosphatemic rickets (ADHR), autosomal recessive hypophosphatemic rickets (ARHR) and tumor-induced osteomalacia (TIO) in addition to other rarer FGF23-mediated conditions. We contrast the FGF23-mediated disorders with FGF23-independent hypophosphatemia, specifically hypophosphatemic rickets with hypercalciuria (HHRH). Errant diagnosis of hypophosphatemic disorders is common. This review aims to enhance the recognition and appropriate diagnosis of hypophosphatemia and to guide appropriate treatment.