Severe hypoglycemia and risk of hospitalization for heart failure in adults with diabetes treated with oral medications with or without insulin: A population-based study

Intermittently scanned continuous glucose monitoring compared with blood glucose monitoring is associated with lower HbA1c and a reduced risk of hospitalisation for diabetes-related complications in adults with type 2 diabetes on insulin therapies

AIMS/HYPOTHESIS

We assessed the impact of initiating intermittently scanned continuous glucose monitoring (isCGM) compared with capillary blood glucose monitoring (BGM) on HbA1c levels and hospitalisations for diabetes-related complications in adults with insulin-treated type 2 diabetes in Sweden.

METHODS

This retrospective comparative cohort study included adults with type 2 diabetes who had a National Diabetes Register initiation date for isCGM after 1 June 2017. Prescribed Drug Register records identified subgroups treated with multiple daily insulin injections (T2D-MDI) or basal insulin (T2D-B), with or without other glucose-lowering drugs. The National Patient Register provided data on hospitalisation rates.

RESULTS

We identified 2876 adults in the T2D-MDI group and 2292 in the T2D-B group with an isCGM index date after 1 June 2017, matched with 33,584 and 43,424 BGM control participants, respectively. The baseline-adjusted difference in the change in mean HbA1c for isCGM users vs BGM control participants in the T2D-MDI cohort was -3.7 mmol/mol (-0.34%) at 6 months, and this was maintained at 24 months. The baseline-adjusted difference in the change in HbA1c for isCGM users vs BGM control participants in the T2D-B cohort was -3.5 mmol/mol (-0.32%) at 6 months, and this was also maintained at 24 months. Compared with BGM control participants, isCGM users in the T2D-MDI cohort had a significantly lower RR of admission for severe hypoglycaemia (0.51; 95% CI 0.27, 0.95), stroke (0.54; 95% CI 0.39, 0.73), acute non-fatal myocardial infarction (0.75; 95% CI 0.57, 0.99) or hospitalisation for any reason (0.84; 95% CI 0.77, 0.90). isCGM users in the T2D-B cohort had a lower RR of admission for heart failure (0.63; 95% CI 0.46, 0.87) or hospitalisation for any reason (0.76; 95% CI 0.69, 0.84).

CONCLUSIONS/INTERPRETATION

This study shows that Swedish adults with type 2 diabetes on insulin who are using isCGM have a significantly reduced HbA1c and fewer hospital admissions for diabetes-related complications compared with BGM control participants.

The association of glycaemic risk factors and diabetes duration with risk of heart failure in people with type 2 diabetes: A systematic review and meta-analysis

AIMS

To conduct a systematic review in order to better understand the association of glycaemic risk factors and diabetes duration with risk of heart failure (HF) in individuals with type 2 diabetes (T2D).

METHODS

We identified longitudinal studies investigating the association of glycaemic factors (glycated haemoglobin [HbA1c], HbA1c variability, and hypoglycaemia) and diabetes duration with HF in individuals with T2D. Hazard ratios and odds ratios were extracted and meta-analysed using a random-effects model where appropriate. Risk of bias assessment was carried out using a modified Newcastle-Ottawa Scale. Egger's test along with the trim-and-fill method were used to assess and account for publication bias.

RESULTS

Forty studies representing 4 102 589 people met the inclusion criteria. The risk of developing HF significantly increased by 15% for each percentage point increase in HbA1c, by 2% for each additional year of diabetes duration, and by 43% for having a history of severe hypoglycaemia. Additionally, variability in HbA1c levels was associated with a 20%-26% increased risk of HF for each unit increase in the metrics of variability (HbA1c standard deviation, coefficient of variation, and average successive variability). All included studies scored high in the risk of bias assessment. Egger's test suggested publication bias, with trim-and-fill analyses revealing a significant 14% increased risk of HF per percentage point increase in HbA1c.

CONCLUSIONS

Glycaemic risk factors and diabetes duration significantly contribute to the heightened risk of HF among individuals with T2D. A reduction in risk of HF is anticipated with better management of glycaemic risk factors.

Insulin augments angiotensin II-induced myocardial fibrosis via the MEK/STAT3 pathway

Regular insulin therapy is significantly related to worse cardiovascular outcomes in patients with type 2 diabetes and heart failure. However, the mechanisms of the causal relationship remain unclear. In this study, we observed the effect of insulin on cardiac structure and function and found that insulin dramatically augmented angiotensin II (Ang II)-induced cardiac dysfunction, as well as the proliferation and collagen production of primary cardiac fibroblasts. Total STAT3 expression, but not activation was stimulated by insulin; the effect of insulin on Ang II-induced fibrosis disappeared when STAT3 was blocked and could be entirely suppressed by the MEK inhibitor PD0325901. Our findings suggest a noninsulin-dependent glucose-lowering regimen for patients with type 2 diabetes (T2DM) and heart failure (HF).

Association of frailty index with congestive heart failure, all-cause and cardiovascular mortality among individuals with type 2 diabetes: a study from National Health and Nutrition Examination Surveys (NHANES), 1999-2018

BACKGROUND

Both type 2 diabetes mellitus (T2DM) and frailty are strongly associated with congestive heart failure (CHF). Individuals with T2DM and CHF have a high frailty burden. The association of frailty with HF, all-cause, and cardiovascular mortality in patients with T2DM has not been thoroughly explored.

METHODS

This study included 2894 adults with T2DM from the National Health and Nutrition Examination Survey (NHANES) database over ten cycles (1999-2018) and followed up for all-cause and cardiovascular mortality through 31 December 2019. The frailty index (FI) was calculated using a 46-item deficit model to assess frailty status. Weighted multivariable logistic regression was performed to explore the relationship between frailty and CHF in patients with T2DM. Weighted restricted cubic splines were used to evaluate the non-linear relationship between FI and outcome. All-cause mortality and cardiovascular mortality association with FI was assessed using the Kaplan-Meier curve and COX proportional hazards regression accounting for sampling weights. Subgroup and sensitivity analyses were performed to evaluate the robustness of the results.

RESULTS

After the adjustment of essential confounders, a higher frailty index in T2DM was associated with increased odds of CHF (odds ratio [OR] for per 1-SD increase, 2.02, 95% confidence interval [CI] 1.67-2.45; P < 0.0001). The presence of frailty T2DM (OR, 3.60; 95% CI 2.34-5.54; P < 0.0001) was associated with a significant increase in the prevalence of CHF compared to non-frailty T2DM in a fully adjusted model. During the median follow-up of 6.75 years, per 1-SD increase in FI was associated with a 41% higher risk of all-cause mortality and a 30% higher risk of cardiovascular mortality after being adjusted for all confounders. Similar results were observed when sensitivity analyses were performed. There was also a non-linear relationship between FI and all-cause mortality. In a weighted multivariate COX proportional model adjusted for full confounders, frailty T2DM increased all-cause (HR, 1.86; 95% CI 1.55-2.24; P < 0.0001) and cardiovascular (HR 1.66; 95% CI 1.18-2.33; P = 0.003) mortality and compared to non-frailty T2DM. The positive association of frailty index and all-cause mortality was only in participants without CHF. The positive association of frailty index and cardiovascular mortality was only in non-anti-diabetic drug users.

CONCLUSIONS

Frailty index in T2DM was positively associated with CHF in linear fashions. The Frailty index was positively correlated with all-cause and cardiovascular death in patients with T2DM. Frailty T2DM was positively associated with CHF, all-cause mortality, and cardiovascular mortality compared to non-frailty T2DM. Promoting frailty measurement and management in T2DM may be beneficial to reduce the burden of CHF and mortality.