Association of waist circumference with haemoglobin A1c and its optimal cutoff for identifying prediabetes and diabetes risk in the Chinese population

The role of non-high-density lipoprotein cholesterol to high-density lipoprotein cholesterol ratio (nhhr) in prediabetes progression and the mediating effect of BMI: a longitudinal study in China

BACKGROUND

Diabetes prevalence in China is significant, with a large proportion in the prediabetes stage. Dyslipidemia is associated with abnormal glucose metabolism, and the non-high-density lipoprotein cholesterol to high-density lipoprotein cholesterol ratio (NHHR) shows potential in diabetes risk assessment, but its role in prediabetes progression is understudied.

METHODS

A longitudinal study from 2011 to 2015 using CHARLS data was conducted. After exclusions, 1408 participants were included. NHHR was calculated from serum TC and HDL - C levels. Diabetes and prediabetes were defined based on standard criteria. Covariates and mediators were assessed, and statistical analyses included logistic regression and mediation analysis, and mediation analysis was conducted to evaluate the involvement of BMI in the association between NHHR and the risk of prediabetes progression.

RESULTS

Among the 1423 people in the cohort analysis, 339 (23.8%) were diagnosed with prediabetes progression. The median NHHR was significantly larger in the progression group (136.99 vs. 124.95, p < 0.05). In the fully adjusted model, NHHR one-unitincrease led to a 10% higher risk. Subgroup analyses showed consistent associations in most subgroups. BMI mediated 33.8% of the NHHR - prediabetes progression association.

CONCLUSION

NHHR is correlated with the risk of prediabetes progressing to diabetes, and BMI may mediate this association. NHHR monitoring could help assess the risk of progression in prediabetes participants.

Exploring the relationships between self-efficacy, self-care, and glycaemic control in primary care diabetes management

Objectives

Our study aimed to identify the complex interplay between self-efficacy, self-care practice, and glycaemic control among people with type 2 diabetes mellitus (PWDs) to inform the design of more targeted and effective behavioural interventions in primary care.

Methods

A cross-sectional descriptive study was performed with 294 PWDs managed in primary care. The Diabetes Management Self-Efficacy Scale (DMSES) and Summary of Diabetes Self-Care Activities (SDSCA) questionnaire measured patients' self-efficacy and self-care practice. Multivariate logistic regression models were developed to explore how SDSCA, DMSES, and their combined effect relate to glycaemic control, adjusting for patient characteristics. Network analysis in R software examined relationships between self-efficacy and self-care dimensions across glycaemic control subgroups using a Gaussian graphical model with the extended Bayesian information criterion.

Results

Half the PWDs (50.7%) had suboptimal glycaemic control. Better glycaemic control was consistently associated with higher self-efficacy (odds ratio (OR) = 0.76, 95% confidence (CI) (0.60, 0.97), p = 0.03), shorter duration of diabetes (OR = 1.89, 95% CI (1.08, 3.31), p = 0.03), normal waist circumference (OR = 1.76, 95% CI (1.02, 3.05), p = 0.04), absence of diabetes complications (OR = 2.09, 95% CI (1.10, 3.98), p = 0.02), and treatment with oral hypoglycaemic agents (OR = 3.05, 95% CI (1.53, 6.09), p < 0.01). Network analysis among people with well-controlled HbA1c revealed that diet adherence and self-efficacy had the most robust connection, with diet self-efficacy strongly associated with most self-efficacy dimensions. Self-efficacy in exercise, blood glucose monitoring, and foot care are the most central factors in the network structures for PWDs with suboptimal glycaemic control.

Conclusions

Our study highlights the critical role of self-efficacy in diabetes primary care. For people with optimal glycaemic control, prioritising self-efficacy in diet adherence is crucial for sustaining glycaemic outcomes and supporting other self-care behaviours. Among those with suboptimal glycaemic control, enhancing self-efficacy in exercise, blood glucose monitoring, and foot care is essential. Targeted education programs, personalised counselling, and E-health tools can further empower patients to manage their diabetes more effectively.

Waist circumference glucose, a novel and effective predictor of type 2 diabetes: a prospective cohort study

Introduction

Waist circumference (WC) and fasting plasma glucose (FPG) have been demonstrated as risk factors for type 2 diabetes mellitus (T2DM). Evidence is limited regarding the association of the combination of WC and FPG (WyG) with the risk of T2DM. The primary aim of the study was to investigate the relationship between WyG and T2DM.

Research design and methods

The current study was a population-based cohort study using data from the NAGALA database. Participants were divided into tertiles based on WyG. Cox proportional hazard regression model was applied to identify the association of WyG with T2DM.

Results

During a median follow-up of 6.19 years in the normoglycemia group and 5.58 years in the prediabetes group, respectively, 88 and 285 individuals in the two groups received a diagnosis of T2DM. After full adjustment, risk of T2DM increased in step-wise fashion with increasing tertiles of WyG. For a per-SD increase in WyG, the hazard ratios for T2DM were 3.05 (95% CI 2.64 - 3.51) in all populations, 1.94 (95% CI 1.46 - 2.58) in the normoglycemia group and 1.63 (95% CI 1.40 - 1.90) in the prediabetes group. The interaction between WyG and fatty liver on T2DM was statistically significant in the prediabetes group (P for interaction = 0.034).

Conclusions

Elevated WyG was independently associated with incident T2DM in Japan. Baseline WyG help identify individuals at high risk of T2DM and implement effective preventive measures.

Adiposity, fat-free mass and incident heart failure in 500 000 individuals

BACKGROUND AND AIMS

The independent role of body fat distribution and fat-free mass in heart failure (HF) risk is unclear. We investigated the role of different body composition compartments in risk of HF.

METHODS

Present analyses include 428 087 participants (mean age 55.9 years, 44% male) from the UK Biobank. Associations of long-term average levels of body composition measures with incident HF were determined using adjusted Cox proportional hazards regression models.

RESULTS

Over a median follow-up of 13.8 years, there were 10 455 first-ever incident HF events. Overall, HF risk was more strongly associated with central adiposity (waist circumference (WC) adjusted for body mass index (BMI); HR 1.38, 95% CI 1.32 to 1.45) than general adiposity (BMI adjusted for WC; HR 1.22, 95% CI 1.16 to 1.27). Although dual X-ray absorptiometry-derived body fat remained positively related to HF after adjustment for fat-free mass (HR 1.37, 95% CI 1.18 to 1.59), the association of fat-free mass with HF was substantially attenuated by fat mass (HR 1.12, 95% CI 1.01 to 1.26) while visceral fat (VAT) remained associated with HF independent of subcutaneous fat (HR 1.20, 95% CI 1.09 to 1.33). In analyses of HF subtypes, HF with preserved ejection fraction was independently associated with all fat measures (eg, VAT: HR 1.23, 95% CI 1.12 to 1.35; body fat: HR 1.36, 95% CI 1.17 to 1.57) while HF with reduced ejection fraction was not independently associated with fat measures (eg, VAT: HR 1.29, 95% CI 0.98 to 1.68; body fat: HR 1.29, 95% CI 0.80 to 2.07).

CONCLUSIONS

This large-scale study shows that excess adiposity and fat mass are associated with higher HF risk while the association of fat-free mass with HF could be explained largely by its correlation with fat mass. The study also describes the independent relevance of body fat distribution to HF subtypes, suggesting different mechanisms may be driving their aetiopathogenesis.

Associations Between Risk Factors of Cardiovascular Disease in Young Adults

Introduction

Cardiovascular disease (CVD) impacts 50% of U.S. adults although few studies evaluate young adults' cardiovascular disease risk. Early identification of cardiovascular disease risk may mitigate increased adulthood incidence. We analyzed (CVD) risk factors and their association with cardiovascular fitness (V ˙ o2max) to devise effective strategies to improve cardiovascular health across the lifespan.

Methods

A cross-sectional study evaluated the effect of a single bout of aerobic exercise on cardiovascular disease risk factors in adults aged 18 to 36 years. Glycemic control (HbA1C), cardiovascular fitness (V ˙ o2max), percent body fat, lean body mass, waist circumference, and body mass index (BMI) were analyzed using correlation analysis and multiple linear regression.

Results

Statistically significant relationships were observed between percent body fat (r = .83, P < .001) and BMI, and waist circumference (r = .83, P < .001) and BMI. Percent body fat (P < .001) and race (P = .018) predicted exercise time, with Asians exercising the longest. Percent fat (P < .001) and HbA1C (P = .039) were identified as predictors of cardiovascular fitness which was low in spite of primarily normal average HbA1C levels.

Conclusions

HbA1C and body fat negatively influence cardiovascular fitness (V ˙ o2max) in young adults increasing adulthood cardiovascular disease risk. Research investigating the effect of HbA1C on cardiovascular health especially in youth is warranted.

Effect of Time-Restricted Eating on Weight Loss in Adults With Type 2 Diabetes: A Randomized Clinical Trial

Importance

Time-restricted eating (TRE) has become increasingly popular, yet longer-term randomized clinical trials have not evaluated its efficacy and safety in patients with type 2 diabetes (T2D).

Objective

To determine whether TRE is more effective for weight reduction and glycemic control than daily calorie restriction (CR) or a control condition in adults with T2D.

Design, Setting, and Participants

This 6-month, parallel-group, randomized clinical trial was performed between January 25, 2022, and April 1, 2023, at the University of Illinois Chicago. Participants were aged 18 to 80 years with obesity and T2D. Data analysis was based on intention to treat.

Interventions

Participants were randomized to 1 of 3 groups: 8-hour TRE (eating 12 to 8 pm only, without calorie counting), CR (25% energy restriction daily), or control.

Main Outcomes and Measures

The primary outcome measure was change in body weight by month 6. Secondary outcomes included changes in hemoglobin A1c (HbA1c) levels and metabolic risk factors.

Results

Seventy-five participants were enrolled with a mean (SD) age of 55 (12) years. The mean (SD) body mass index (calculated as weight in kilograms divided by height in meters squared) was 39 (7) and the mean (SD) HbA1c level was 8.1% (1.6%). A total of 53 participants (71%) were women. One participant (1%) was Asian, 30 (40%) were Hispanic White, 40 (53%) were non-Hispanic Black, and 4 (5%) were non-Hispanic White. Participants in the TRE group were adherent with their eating window on a mean (SD) of 6.1 (0.8) days per week, and 17 (68%) in the CR group were adherent with their prescribed calorie goals over 6 months. The mean (SD) reduction in energy intake was -313 (509) kcal/d for TRE, -197 (426) kcal/d for CR, and -16 (439) kcal/d for controls. By month 6, body weight decreased significantly in the TRE group (-3.56% [95% CI, -5.92% to -1.20%]; P = .004) but not the CR group (-1.78% [95% CI, -3.67% to 0.11%]; P = .06), relative to controls. Levels of HbA1c decreased in the TRE (-0.91% [95% CI, -1.61% to -0.20%]) and CR (-0.94% [95% CI, -1.59% to -0.30%]) groups, relative to controls, with no differences between the TRE and CR groups. Time in euglycemic range, medication effect score, blood pressure, and plasma lipid levels did not differ among groups. No serious adverse events were reported.

Conclusions and relevance

This randomized clinical trial found that a TRE diet strategy without calorie counting was effective for weight loss and lowering of HbA1c levels compared with daily calorie counting in a sample of adults with T2D. These findings will need to be confirmed by larger RCTs with longer follow-up.

Trial Registration

ClinicalTrials.gov Identifier: NCT05225337.