Effects of hyperbaric oxygen on blood glucose levels in patients with diabetes mellitus, stroke or traumatic brain injury and healthy volunteers: a prospective, crossover, controlled trial.

INTRODUCTION: A decrease in blood glucose levels (BGL) during hyperbaric oxygen treatment (HBOT) is a well-recognised phenomenon, but studies of this are limited and inconclusive. This study evaluated the effect of HBOT on BGL in patients with diabetes mellitus (DM), traumatic brain injury (TBI) or stroke and healthy volunteers in a prospective, open, controlled trial. METHODS: Thirty-nine participants were enrolled and evaluated twice: once during HBOT (90 minutes at 203 kPa), and once during a control session on normobaric air. Sessions were held up to two weeks apart and participants were instructed to eat the same diet. BGL was measured before, during and at the completion of each session. RESULTS: For the whole study group, there was a small but statistically significant decrease in BGL in both the HBOT (7.27 ± 3.66 mmol⁻¹ before to 6.71 ± 3.88 mmol ⁻¹ after, P = 0.037) and control (air) sessions (7.43 ± 3.49 mmol L⁻¹ before to 6.71 ± 3.77 mmol L⁻¹ after, P = 0.004). This fall did not differ between the two conditions (P = 0.59). Examining the three groups separately, BGL fell in all three subgroups, but this fall was only statistically significant for the air session in the diabetic group. There were no statistically significant differences in the BGL reduction when HBOT was compared to normobaric air in any of the three subgroups. CONCLUSIONS: BGL may decrease during HBOT and accordingly it should be monitored before entering the chamber. However, this decrease in BGL should probably not be attributed to the hyperbaric environment per se.

The effect of sitagliptin versus glibenclamide on arterial stiffness, blood pressure, lipids, and inflammation in type 2 diabetes mellitus patients.

AIM: This study evaluated the effect of sitagliptin versus glibenclamide on arterial stiffness, blood pressure, lipid profile, oxidative stress, and high-sensitivity C-reactive protein (hsCRP) in type 2 diabetes mellitus patients. SUBJECTS AND METHODS: Forty diabetes patients, inadequately controlled on metformin, were randomly assigned to either sitagliptin (100 mg/day) or glibenclamide (5 mg/day) for 3 months. Following a 1-month washout period, a crossover switch from glibenclamide to sitagliptin and vice versa was performed for an additional 3 months. Arterial stiffness, 24-h ambulatory blood pressure monitoring, lipids, hsCRP, glycated hemoglobin, fasting glucose, STAT-8-isoprostane (a measure of oxidative stress), body mass index (BMI), and waist circumference were measured at baseline and at 3 months with each of the study drugs. RESULTS: Thirty-four patients completed the study. Glibenclamide had a better glucose-lowering effect than sitagliptin, but this was associated with more hypoglycemic events. BMI increased following glibenclamide treatment, whereas sitagliptin proved weight-neutral. Mean BMI gain was +0.5±1.0 kg/m(2) for glibenclamide versus -0.01±0.9 kg/m(2) for sitagliptin (P<0.001). Triglyceride levels significantly dropped following sitagliptin, although they remained unaltered after glibenclamide treatment. Mean triglyceride decrease was -18.4±45 mg/mL after sitagliptin but -0.2±57 mg/dL following glibenclamide treatment (P=0.018). There was no change in low-density lipoprotein, high-density lipoprotein, arterial stiffness, blood pressure monitoring, hsCRP, or STAT-8-isoprostane with each of the study drugs. CONCLUSIONS: Sitagliptin, but not glibenclamide, demonstrated a significant beneficial effect on BMI and triglyceride levels. However, arterial stiffness, blood pressure, oxidative stress, and inflammatory status were not significantly affected by adding sitagliptin or glibenclamide to metformin-treated type 2 diabetes patients.

The effect of levothyroxine on arterial stiffness and lipid profile in patients with subclinical hypothyroidism.

BACKGROUND: The influence of treatment for subclinical hypothyroidism (SCH) on cardiovascular morbidity and mortality, arterial stiffness, and lipid profile has not been elucidated yet. The aim of this study was to evaluate the effect of levothyroxine on arterial stiffness, lipid profile, and inflammation. METHODS: The study included 30 patients with SCH. Patients were treated with levothyroxine and were assessed at baseline and at 1, 4, and 7 months. Blood samples were taken for lipid profile and highly sensitive C-reactive protein (hs-CRP). Arterial stiffness was evaluated by augmentation index (AIx). In conditions that cause arterial stiffness, the pulse wave traveling from the periphery to the heart reaches the heart during systole, resulting in augmentation of the central pressure. This increase, calculated as the AIx, is a good expression of central aortic pressure. RESULTS: After accomplishing euthyroidism, the AIx decreased from 17.2 +/- 8.3 to 14.3 +/- 6.5 (p < 0.01) and AIx percentage decreased from 36.2 +/- 11.5 to 33.2 +/- 9.1 (p = 0.03). Systolic blood pressure (SBP) decreased from 134.7 +/- 20 to 127.6 +/- 13.7 mmHg (p < 0.01). In those patients whose AIx decreased, low-density lipoprotein (LDL) levels decreased by 0.4 +/- 0.96 mmol/L compared to the patients whose AIx did not decrease and LDL increased by 0.62 +/- 1.48 mmol/L (p = 0.057). Total cholesterol decreased by 0.72 +/- 1.64 mmol/L in the patients whose AIx decreased and increased by 1 +/- 2.53 mg/dL in the patients whose AIx did not improve (p = 0.06). CONCLUSIONS: In patients with SCH, treatment with levothyroxine had a significant beneficial effect on arterial stiffness and SBP, and no effect on lipid profile or hs-CRP.