Continuous Glucose Monitoring Alarms in Adults with Type 1 Diabetes: User Characteristics and the Impact of Hypoglycemia and Hyperglycemia Alarm Thresholds on Glycemic Control

Background: Few studies have evaluated the implications of the alarm thresholds of continuous glucose monitoring (CGM) systems for individuals with diabetes. The present study aimed to investigate the influence of hypoglycemia and hyperglycemia alarm thresholds on glycemic control in adults with type 1 diabetes (T1DM) and the characteristics of patients who use these alarms more frequently. Methods: This observational cross-sectional study included 873 users of the FreeStyle Libre 2 system (501 men, median age 48 years, range 18-90 years) with T1DM from a single center. We investigated the role of demographic and metabolic factors on the use of alarms and the impact of hypoglycemia and hyperglycemia alarms and their thresholds on glycemic control. Results: Alarm users were older than nonusers (median age 49 vs. 43 years, respectively; P < 0.001). The hypoglycemia alarms were set by 76.1% of women and by 69.1% of men (P = 0.022). The hypoglycemia alarms reduced hypoglycemia features and glucose variability, although at the expense of shorter time in range. The higher the hypoglycemia alarm threshold, the greater these effects. The hyperglycemia alarms were effective in reducing hyperglycemia and lowering the glucose management indicator, although at the expense of a greater tendency to hypoglycemia. The lower the hyperglycemia alarm threshold, the greater these effects. Conclusions: CGM alarms contribute to better glycemic control. However, hypoglycemia and hyperglycemia alarms have advantages and disadvantages. Adults with T1DM should explore, under medical supervision, which alarm thresholds will best help them achieve their individual glycemic goals.

Hypoglycemia during hyperosmolar hyperglycemic crises is associated with long-term mortality

BACKGROUND

Previous research has indicated that hypoglycemia during hospitalization is a predictor of unfavorable outcomes in patients with diabetes. However, no studies have examined the long-term impact of hypoglycemia in adults admitted for hyperglycemic crises. The study was aimed to investigate the long-term implications of hypoglycemia during hyperosmolar hyperglycemic crises, particularly in terms of all-cause mortality.

METHODS

This retrospective cohort study included 170 patients (82 men [48.2%], median age 72 years) admitted to a university hospital for hyperosmolar hyperglycemic crises, including pure hyperosmolar hyperglycemic states and hyperosmolar diabetic ketoacidoses. We separately investigated the prognostic significance of hypoglycemia on mortality during the initial intravenous insulin therapy phase and during the later subcutaneous insulin therapy phase, both during hospitalization and in the long term (median follow-up, 652 days; range 2-3460 days).

RESULTS

Both hypoglycemia during the initial intravenous insulin therapy phase (observed in 26.5% of patients) and hypoglycemia during the later subcutaneous insulin therapy phase (observed in 52.7% of patients) were associated with long-term mortality. After adjusting for potential confounders, hypoglycemia during the initial intravenous insulin therapy phase remained associated with mortality (hazard ratio 2.10, 95% CI 1.27-3.46, p = 0.004).

CONCLUSIONS

Hypoglycemia during hyperosmolar hyperglycemic crises is a marker of long-term mortality, especially when it occurs during the initial intravenous insulin therapy phase.

Metformin and Glucose Concentration as Limiting Factors in Retinal Pigment Epithelial Cell Viability and Proliferation

Metformin is a well-established drug for the treatment of type 2 diabetes; however, the mechanism of action has not been well described and many aspects of how it truly acts are still unknown. Moreover, regarding in vitro experiments, the glycaemic status when metformin is used is generally not considered, which, added to the suprapharmacological drug concentrations that are commonly employed in research, has resulted in gaps of its mechanism of action. The aim of this study was to determine how glucose and metformin concentrations influence cell culture. Considering that diabetic retinopathy is one of the most common complications of diabetes, a retinal pigment epithelial cell line was selected, and cell viability and proliferation rates were measured at different glucose and metformin concentrations. As expected, glucose concentration by itself positively influenced cell proliferation rates. When the metformin was considered, results were conditioned, as well, by metformin concentration. This conditioning resulted in cell death when high concentrations of metformin were used under physiological concentrations of glucose, while this did not happen when clinically relevant concentrations of metformin were used independently of glucose status. Our study shows the importance of in vitro cell growth conditions when drug effects such as metformin's are being analysed.

Hypoglycemia in patients with type 2 diabetes mellitus during hospitalization: associated factors and prognostic value

BACKGROUND

The risk factors for hypoglycemia during hospital admission and its consequences in patients with diabetes are not entirely known. The present study aimed to investigate the risk factors for hypoglycemia, as well as the potential implications of hypoglycemia in patients with type 2 diabetes mellitus admitted to the hospital.

METHODS

This retrospective cohort study included 324 patients (214 [66.0%] men; median age 70 years, range 34-95 years) with type 2 diabetes admitted to a university hospital who were consulted the Endocrinology Department for glycemic control during a 12-month period. We investigated the potential role of demographic factors, metabolic factors, therapy, and comorbidities on the development of in-hospital hypoglycemia. We explored the prognostic value of hypoglycemia on mortality (both in-hospital and in the long-term), hospital readmission in the following year, and metabolic control (HbA1c value) after discharge (median follow-up, 886 days; range 19-1255 days).

RESULTS

Hypoglycemia occurred in 154 (47.5%) patients during their hospitalization and was associated with advanced age, previous insulin therapy, higher Charlson Comorbidity Index, lower body mass index and lower baseline HbA1c values. Hypoglycemia was associated with greater in-hospital and long-term mortality, longer hospital stays, higher readmission rates, and poorer metabolic control after discharge. These negative consequences of hypoglycemia were more frequent in patients with severe (≤ 55 mg/dL) hypoglycemia and in patients who had hypoglycemia during a greater percentage of hospitalization days.

CONCLUSIONS

Hypoglycemia during hospital admission is a marker of a poor prognosis in patients with type 2 diabetes.

Anaphylaxis to Vespa velutina nigrithorax: Pattern of Sensitization for an Emerging Problem in Western Countries

OBJECTIVE

To define the sensitization pattern of patients with anaphylaxis to Vespa velutina nigrithorax (VVN).

METHODS

We studied 100 consecutive Spanish patients with anaphylaxis to Hymenoptera venom and systematically determined specific IgE (sIgE) to whole venoms (Vespula species, Polistes dominula, Apis mellifera, Vespa crabro, and Dolichovespula maculata) and their molecular components (rApi m 1, rApi m 5, rApi m 10, rVes v 1, rVes v 5, rPol d 5, and cross-reactive carbohydrates). Specific IgE to VVN venom and its antigen 5 (nVesp v 5) were measured in a subsample.

RESULTS

Seventy-seven patients had anaphylaxis to VVN. Of these, only 16 (20.8%) reported previous VVN stings, but were stung by other Hymenoptera. Positive sIgE (>0.35 kUA/L) to each of the whole venoms was detected in >70% of patients (Vespula species in 100%). The components showing >50% positivity were rApi m 5 (51.4%), rPol d 5 (80.0%), and rVes v 5 (98.7%). This pattern was similar to that of Vespula species anaphylaxis (n=11) but different from that of A mellifera anaphylaxis (n=10). Specific IgE to nVesp v 5 was positive in all patients (n=15) with VVN anaphylaxis and was correlated with sIgE to both rVes v 5 (R=0.931) and rPol d 5 (R=0.887).

CONCLUSIONS

VVN has become the commonest cause of Hymenoptera anaphylaxis in our area. Most cases report no previous VVN stings. Their sensitization pattern is similar to that of patients with anaphylaxis to other Vespidae. Specific IgE to antigen-5 from VVN, Vespula species, and P dominula are strongly correlated in patients with VVN anaphylaxis.