Serum HMGB1 levels are independently associated with glucose clamp-derived measures of insulin resistance in women with PCOS.

PURPOSE: PCOS is associated with low grade inflammation which could play a role in insulin resistance and ovarian dysfunction. Preliminary findings suggested that serum levels of HMGB1, a cytokine involved in inflammation, might be altered in women with PCOS. Primary aim of this study was to assess whether HMGB1 serum concentrations are associated with PCOS and with the state of insulin resistance of these women. METHODS: Sixty women with PCOS, selected to have a similar proportion of subjects with altered or normal insulin sensitivity, and 29 healthy controls were studied. Serum HMGB1 levels were compared in subgroups of PCOS women and controls. In PCOS women, insulin sensitivity was assessed by the glucose clamp technique and HMGB1 was measured at baseline and after acute hyperinsulinemia. RESULTS: HMGB1 levels were similar in women with PCOS and controls and no elements used for diagnosing PCOS were associated with serum HMGB1. However, HMGB1 concentrations were higher in insulin-resistant vs insulin-sensitive PCOS women (p = 0.017), and inversely associated with insulin-induced total and non-oxidative glucose metabolism. In both subgroups of PCOS women, serum HMBG1 levels significantly increased after acute hyperinsulinemia. CONCLUSIONS: These data suggest that HMGB1 levels are not associated with PCOS per se, but with insulin resistance. Further research should establish the underlying nature of this relationship, and whether this protein might play a role in the metabolic complications of PCOS.

The value of cough peak flow in the assessment of cough efficacy in neuromuscular patients. A cross sectional study.

BACKGROUND: Cough efficacy assessment is of clinical relevance in neuromuscular patients. Tests of varying complexity and invasiveness, such as cough peak flow (CPF), maximal expiratory pressure (PEmax) and gastric pressure during cough (Cough Pgas) are routinely available. AIM: To assess the value of CPF, PEmax and Cough Pgas in the detection of ineffective cough in patients suffering from neuromuscular diseases. DESIGN: Prospective observational study. SETTING: Outpatient laboratory for respiratory muscle function assessment. POPULATION: Forty-nine patients with neuromuscular diseases (25 F, age 50 ± 15 years). METHODS: Each patient performed spirometry, CPF, PEmax, Cough Pgas and maximal inspiratory pressure (PImax). Normal values for each test were determined from published and in-house lab data. RESULTS: In all patients, vital capacity ranged from 46 to 119% of pred. Twenty seven percent of patients resulted under the lower normal limit of CPF and this percentage was significantly lower as compared to that of PEmax and Cough Pgas (51% and 53% respectively, P=0.013). Combining all three tests, the percentage of patients resulting below normal was 22% (P=0.638, as compared to CPF results alone). Additionally, CPF correlated significantly with PImax, PEmax, and Cough Pgas (P<0.01 for each correlation) and by multiple regression analysis PImax and PEmax contributed 65% of CPF variance. CONCLUSION: Our study shows that in neuromuscular patients, PEmax and Cough Pgas values may overdiagnose an ineffective cough. CPF, a non invasive and easy to perform test, is a global measure of voluntary cough. CLINICAL REHABILITATION SETTING:CPF may be relevant in the routine evaluation of patients with neuromuscular diseases, both in research and in rehabilitation settings.