Acute changes in plasma glucose increases left ventricular systolic function in insulin-treated patients with type 2 diabetes and controls

Assessing the temporal within-day glycemic variability during hospitalization in patients with type 2 diabetes patients using continuous glucose monitoring: a retrospective observational study

AIMS

Frequent and extensive within-day glycemic variability (GV) in blood glucose levels may increase the risk of hypoglycemia and long-term mortality in hospitalized patients with diabetes. We aimed to assess the amplitude and frequency of within-day GV in inpatients with type 2 diabetes and to explore the factors influencing within-day GV.

METHODS

We conducted a single-center, retrospective observational study by analyzing hospital records and 10-day real-time continuous glucose monitoring data. Within-day GV was assessed using the coefficient of variation (%CV). The primary outcome was the amplitude and frequency of within-day GV. The frequency of within-day GV was assessed by the consecutive days (CD) of maintaining within the target %CV range after first reaching it (CD after first reaching the target) and the maximum consecutive days of maintaining within the target %CV range (Max-CD). The target %CV range was less than 24.4%. We evaluated the factors influencing within-day GV using COX regression and Poisson regression models.

RESULTS

A total of 1050 cases were analyzed, of whom 86.57% reduced the amplitude of within-day GV before the sixth day of hospitalization. Of the 1050 hospitalized patients, 66.57% stayed within the target %CV range for less than two days after first reaching the target and 69.71% experienced a Max-CD of fewer than four days. Reducing the average postprandial glucose excursion (hazard ratio [HR]: 0.81, 95% confidence interval [CI]: 0.77-0.85; incidence rate ratios [IRR]: 0.72, 95% CI: 0.69-0.74) and the use of α-glucosidase inhibitors (IRR: 1.1, 95% CI: 1.01-1.18) and glucagon-like peptide-1 agonist (IRR: 1.30, 95% CI: 1.02-1.65) contributed to reducing the amplitude and decreasing the frequency of within-day GV. However, the use of insulin (HR: 0.64, 95% CI: 0.55-0.75; IRR: 0.86, 95% CI: 0.79-0.93) and glinide (HR: 0.47, 95% CI: 0.31-0.73; IRR: 0.84, 95% CI: 0.73-0.97) may lead to an increased frequency of within-day GV.

CONCLUSIONS

An increasing frequency of within-day GV was observed during the hospitalization in patients with type 2 diabetes, despite the effective reduction in the amplitude of within-day GV. Using medications designed to lower postprandial blood glucose could contribute to minimize the risk of frequent within-day GV.

Hypoglycaemia and rebound hyperglycaemia increase left ventricular systolic function in patients with type 1 diabetes

AIM

To investigate echocardiographic changes during acute hypoglycaemia followed by recovery to hyperglycaemia or euglycaemia in patients with type 1 diabetes.

MATERIALS AND METHODS

In a randomized crossover study, 24 patients with type 1 diabetes took part in two experimental study days, consisting of a hyperinsulinaemic-euglycaemic phase (5.0-8.0 mmol/L) for 45 minutes followed by a hyperinsulinemic-hypoglycaemic phase (2.5 mmol/L) for 60 minutes, and a recovery phase in either hyperglycaemia (20 mmol/L) or euglycaemia (5.0-8.0 mmol/L) for 60 minutes. Cardiac function was evaluated with echocardiography during each phase.

RESULTS

Acute hypoglycaemia increased all markers of left ventricular (LV) systolic function, including LV ejection fraction (LVEF), global longitudinal strain (GLS), GLS rate and peak systolic velocity of mitral annular longitudinal movement (s'; P < 0.001 for all). During the recovery phases, all markers of LV systolic function were increased during hyperglycaemia (P < 0.01 for all), and LVEF and GLS remained increased during euglycaemia (P = 0.0116 and P = 0.0092, respectively). The increment in LVEF during the recovery phase was greater during hyperglycaemia than euglycaemia (P = 0.0046).

CONCLUSIONS

Hypoglycaemia, recent hypoglycaemia, and overcorrection of hypoglycaemia to rebound hyperglycaemia increased LV systolic function in type 1 diabetes and may imply consideration of plasma glucose when evaluating LV function in patients with type 1 diabetes. An increase in LV systolic function may cause increased strain on the heart and partly explain the link between hypoglycaemia, high glycaemic variability and cardiovascular disease.