Sex hormone-binding globulin (SHBG) has emerged as one of the multiple genetic and environmental factors that potentially contribute to the pathophysiology of Type 2 diabetes mellitus (T2DM). In addition to epidemiologic studies demonstrating a consistent relationship between decreased levels of serum SHBG and incident T2DM, recent genetic studies also reveal that transmission of specific polymorphisms in the SHBG gene influence risk of T2DM. On the molecular level, elucidation of the multiple interactions between SHBG and its receptors in various target tissues, suggest physiologic roles for SHBG that are more complex than the simple transport of sex hormones in serum. Taken together, these data provide support for an expanded role of SHBG in the pathophysiology of insulin resistance and T2DM.

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Bone disease is a frequent complication in adolescents and adults with cystic fibrosis (CF). Early detection and monitoring of bone mineral density and multidisciplinary preventive care are necessary from childhood through adolescence to minimize CF-related bone disease (CFBD) in adult CF patients. Approaches to optimizing bone health include ensuring adequate nutrition, particularly intake of calcium and vitamins D and K, addressing other secondary causes of low bone density such as hypogonadism, encouraging weight bearing exercise, and avoiding bone toxic medications. Of the currently available anti-resorptive or anabolic osteoporosis medications, only bisphosphonates have been studied in individuals with CF. Future studies are needed to better understand the optimal approach for managing CFBD.

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Aims: Human placental lactogen (hPL) acts via the prolactin receptor (PRLR) on maternal b-cells to mediate increases in b-cell mass and function during normal pregnancy. This interaction between hPL and PRLR is essential to maintain normal glucose homeostasis and to address the increased metabolic demands of pregnancy. Given the importance of the PRLR-hPL axis in pancreatic islet cell adaptation to pregnancy, we hypothesized that genetic variation in the PRLR gene could influence risk of development of gestational diabetes mellitus (GDM). DNA samples from 96 mothers affected by GDM and 96 unaffected cases were genotyped for 8 selected single nucleotide polymorphisms (SNPs) in PRLR. Results: Significant associations were identified in two SNPs analyzed. The minor alleles of PRLR SNPs rs10068521 and rs9292578 were more frequently observed in GDM cases than controls and were associated with a 2.36-fold increased risk for GDM in those carrying the minor allele. Conclusion: SNPs of the PRLR gene 5¢ UTR and promoter region are associated with increased risk for GDM in a population of Chilean subjects.