Background: In humans, adiponectin has been demonstrated to circulate in inverse proportion to the degree of insulin resistance. Objective: To investigate the association between adiponectin and glycosylated haemoglobin (HbA 1c ) in a population-based study. Design and methods: Two hundred and ninety-seven individuals aged 30 -75 years were enrolled in a cross-sectional study. They included patients with type 2 (non-insulin-dependent) diabetes mellitus and stable, good metabolic control (n ¼ 32) and individuals with glucose intolerance (n ¼ 54). Adiponectin was measured using a sandwich enzyme-linked immunosorbent assay (intra-assay and interassay coefficients of variation 3.3 and 7.4% respectively). Results: Adiponectin correlated with age (r ¼ 0.161; P ¼ 0.006), body mass index (r ¼ 2 0.197; P ¼ 0.001), diastolic blood pressure (r ¼ 2 0.181; P ¼ 0.005), fasting glucose and HbA 1c (r ¼ 2 0.251 and r ¼ 20.22 respectively; P , 0.0001), high-density lipoprotein cholesterol (r ¼ 0.442; P , 0.001) and serum triglycerides (r ¼ 2 362; P , 0.001). In multiple regression analysis, sex, age, fasting and post-load glucose, and adiponectin independently contributed to 40% of the variance in HbA 1c . Among individuals with normal glucose tolerance, fasting glucose (P ¼ 0.0033), post-load glucose (P ¼ 0.0015), age (P ¼ 0.001) and adiponectin (P ¼ 0.0083) independently contributed to 21% of the variance in HbA 1c . Conclusion: Adiponectin is significantly associated with altered glucose metabolism and independently contributes to the variance of HbA 1c in a population-based manner.

Objective: Adiponectin protects against liver dysfunction in insulin-resistant states such as obesity and type 2 diabetes (T2DM), but the role of adiponectin receptors in this disorder is largely unknown. We studied whether common single-nucleotide polymorphisms (SNPs) in ADIPOR1 and ADIPOR2 are associated with liver function tests (LFTs) in human subjects with various degrees of insulin resistance. Methods and Procedures: Serum alanine (ALT) and aspartate (AST) aminotransferases, homeostasis model assessment of insulin resistance (HOMA-IR), -8503 G/A (rs6666089) and +5843 C/T (rs1342387) SNPs in ADIPOR1, -64,241 T/G (rs1029629) and +33447 C/T (rs1044471) SNPs in ADIPOR2 were assessed in 700 white subjects from a population-based study. Results: In nondiabetic subjects, the at-risk alleles for the common -64,241 T/G and +33447 C/T SNPs in ADIPOR2 were associated with increased circulating adiponectin (P < 0.05 to P < 0.005), but not with LFT. Conversely, in T2DM subjects (who are at risk for liver dysfunction), the same alleles were associated with increased serum ALT and AST (P < 0.05 to P < 0.0001), but not with circulating adiponectin. No significant associations with these parameters were evident for the common -8503 G/A and +5843 C/T SNPs in ADIPOR1. In a replication study, the -64,241 T/G and +33447 C/T SNPs in ADIPOR2 were associated with ALT and AST (P < 0.05 to P < 0.0001) in pooled obese and T2DM subjects. Discussion: Common SNPs in ADIPOR2 are associated with LFT in T2DM subjects, which suggests a possible role of this receptor in liver dysfunction associated with insulin resistance.

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Pituitary macroadenomas (more than 10 mm in diameter) are infrequent as casual findings and optimal management strategy for these tumours has not been established. Neurosurgical approach must be always considered in patients with visual field defects or with hormone-secreting adenomas (but prolactinoma), and in those with evidence of lesion's growth or if clinical pituitary apoplexy occurs. We present two cases in which surgical indication was based on patient's young age (case number one), and on hypogonadal status, in a male patient not suitable of androgen substitution (case number two). We also discuss the benefits of including such unusual indications for neurosurgical treatment into the incidentally discovered pituitary macroadenomas evaluation strategy.

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