Short-acting insulin analogues versus regular human insulin on postprandial glucose and hypoglycemia in type 1 diabetes mellitus: a systematic review and meta-analysis.

INTRODUCTION: Strict glucose control using multiple doses of insulin is the standard treatment for type 1 diabetes mellitus (T1DM), but increased risk of hypoglycemia is a frequent drawback. Regular insulin in multiple doses is important for achieving strict glycemic control for T1DM, but short-acting insulin analogues may be better in reducing hypoglycemia and postprandial glucose levels. OBJECTIVE: We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) to assess the effects of short-acting insulin analogues vs regular human insulin on hypoglycemia and postprandial glucose in patients with T1DM. METHODS: Searches were run on the electronic databases MEDLINE, Cochrane-CENTRAL, EMBASE, ClinicalTrials.gov, LILACS, and DARE for RCTs published until August 2017. To be included in the study, the RCTs had to cover a minimum period of 4 weeks and had to assess the effects of short-acting insulin analogues vs regular human insulin on hypoglycemia and postprandial glucose levels in patients with T1DM. Two independent reviewers extracted the data and assessed the quality of the selected studies. The primary outcomes analyzed were hypoglycemia (total episodes, nocturnal hypoglycemia, and severe hypoglycemia) and postprandial glucose (at all times, after breakfast, after lunch, and after dinner). Glycated hemoglobin (HbA1c) levels and quality of life were considered secondary outcomes. The risk of bias of each RCT was assessed using the Cochrane Collaboration Risk of Bias table, while the quality of evidence for each outcome was assessed using the GRADEpro software. The pooled mean difference in the number of hypoglycemic episodes and postprandial glucose between short-acting insulin analogues vs. regular human insulin was calculated using the random-effects model. RESULTS: Of the 2897 articles retrieved, 22 (6235 patients) were included. Short-acting insulin analogues were associated with a decrease in total hypoglycemic episodes (risk rate 0.93, 95% CI 0.87-0.99; 6235 patients; I2 = 81%), nocturnal hypoglycemia (risk rate 0.55, 95% CI 0.40-0.76, 1995 patients, I2 = 84%), and severe hypoglycemia (risk rate 0.68, 95% CI 0.60-0.77; 5945 patients, I2 = 0%); and with lower postprandial glucose levels (mean difference/MD - 19.44 mg/dL; 95% CI - 21.49 to - 17.39; 5031 patients, I2 = 69%) and lower HbA1c (MD - 0,13%; IC 95% - 0.16 to - 0.10; 5204 patients; I2 = 73%) levels. CONCLUSIONS: Short-acting insulin analogues are superior to regular human insulin in T1DM patients for the following outcomes: total hypoglycemic episodes, nocturnal hypoglycemia, severe hypoglycemia, postprandial glucose, and HbA1c.

Fast acquisition sagittal T1 magnetic resonance imaging (FAST1-MRI): a new imaging approach for the diagnosis of growth hormone deficiency.

Routine magnetic resonance imaging (MRI) is an established standard method to investigate the etiology of pituitary insufficiency. Among the anatomic abnormalities usually observed, ectopic hyperintense signal on T1 sequence is the most frequently associated with pituitary dysfunction. We developed a new protocol (FAST1-MRI) which is able to detect anatomic hypothalamic-pituitary abnormalities with 100% concordance when compared to the routine MRI protocol. FAST1-MRI takes only 3.25 minutes, and is performed without contrast, sedation or anesthesia. We studied 17 controls and 31 patients with growth hormone (GH) deficiency (18/31 with abnormal MRI). Patients with ectopic hyperintense signal were shorter in height, had lower IGF-I and IGFBP-3 levels, and reduced GH response after clonidine. In conclusion, we describe a new simplified MRI protocol that we propose should be used in the diagnosis of GH deficiency.

Partial glucocorticoid resistance in obese children detected by very low dose dexamethasone suppression test.

The effects of glucocorticoids (GC) are mediated by the activation of specific receptors that can be quantified in vitro by several laboratory tests. In vivo, other tests to determine GC sensitivity have been described, but only employing pharmacological doses. In this study, we used a very low dose of dexamethasone, an in vivo model to assess individual GC sensitivity. Fifty-five obese children and adolescents and 17 controls were studied. The patients were submitted to four 12-h urine collections, starting at 22:00 h; dexamethasone was administered orally at the end of the second urine sample. Patients were divided in the following groups: group Ob75 (n = 29) and the control group (n = 17) received dexamethasone 75 microg/m2, and group Ob150 (n = 26) received dexamethasone 150 microg/m2. Urinary cortisol was determined by RIA and expressed as microg/m2/12 h. All patients and controls showed a circadian rhythm before GC, which was maintained after dexamethasone only in controls. In the obese patients the circadian rhythm was abolished following both doses of dexamethasone, but more prominently with the dose of 150 microg/m2. In the obese group given 75 microg/m2, urinary cortisol inhibition was only observed in the first 12 h after dexamethasone, suggesting a partial and shorter suppression of the hypothalamic-pituitary axis. In both control and obese patients, the very low dose of dexamethasone was able to create a gradient of cortisol suppression that could be useful to identify an individual's sensitivity to glucocorticoids.