Relationship of glycated hemoglobin A1c, coronary artery calcification and insulin resistance in males without diabetes

Glycaemic Effects of a 156-km Ultra-trail Race in Athletes: An Observational Field Study

BACKGROUND

Ultra-trail running races pose appreciable physiological challenges, particularly for glucose metabolism. Previous studies that yielded divergent results only measured glycaemia at isolated times.

OBJECTIVES

We aimed to explore the impact of an ultra-endurance race on continuously measured glycaemia and to understand potential physiological mechanisms, as well as the consequences for performance and behavioural alertness.

METHODS

Fifty-five athletes (78% men, 43.7 ± 9.6 years) ran a 156-km ultra-trail race (six 26-km laps, total elevation 6000 m). Participants wore a masked continuous glucose monitoring sensor from the day before the race until 10 days post-race. Blood was taken at rest, during refuelling stops after each lap, and after 24-h recovery. Running intensity (% heart rate reserve), performance (lap times), psychological stress, and behavioural alertness were explored. Linear mixed models and logistic regressions were carried out.

RESULTS

No higher risk of hypo- or hyperglycaemia was observed during the exercise phases of the race (i.e. excluding stops for scientific measurements and refuelling) compared with resting values. Laps comprising a greater proportion of time spent at maximal aerobic intensity were nevertheless associated with more time > 180 mg/dL (P = 0.021). A major risk of hyperglycaemia appeared during the 48-h post-race period compared with pre-race (P < 0.05), with 31.9% of the participants spending time with values > 180 mg/dL during recovery versus 5.5% during resting. Changes in circulating insulin, cortisol, and free fatty acids followed profiles comparable with those usually observed during traditional aerobic exercise. However, creatine phosphokinase, and to a lesser extent lactate dehydrogenase, increased exponentially during the race (P < 0.001) and remained high at 24-h post-race (P < 0.001; respectively 43.6 and 1.8 times higher vs. resting). Glycaemic metrics did not influence physical performance or behavioural alertness.

CONCLUSION

Ultra-endurance athletes were exposed to hyperglycaemia during the 48-h post-race period, possibly linked to muscle damage and inflammation. Strategies to mitigate muscle damage or subsequent inflammation before or after ultra-trail races could limit recovery hyperglycaemia and hence its related adverse health consequences.

TRIAL REGISTRATION NUMBER

NCT05538442 2022-09-21 retrospectively registered.

Association between the homeostasis model assessment of insulin resistance and coronary artery calcification: a meta-analysis of observational studies

Background

Insulin resistance (IR), a risk factor for cardiovascular diseases, has garnered significant attention in scientific research. Several studies have investigated the correlation between IR and coronary artery calcification (CAC), yielding varying results. In light of this, we conducted a systematic review to investigate the association between IR as evaluated by the homeostasis model assessment (HOMA-IR) and CAC.

Methods

A comprehensive search was conducted to identify relevant studies in PubMed, Embase, Scopus, and Web of Science databases. In addition, preprint servers such as Research Square, BioRxiv, and MedRxiv were manually searched. The collected data were analyzed using either fixed or random effects models, depending on the heterogeneity observed among the studies. The assessment of the body of evidence was performed using the GRADE approach to determine its quality.

Results

The current research incorporated 15 studies with 60,649 subjects. The analysis revealed that a higher category of HOMA-IR was associated with a greater prevalence of CAC in comparison to the lowest HOMA-IR category, with an OR of 1.13 (95% CI: 1.06-1.20, I2 = 29%, P < 0.001). A similar result was reached when HOMA-IR was analyzed as a continuous variable (OR: 1.27, 95% CI: 1.14-1.41, I2 = 54%, P < 0.001). In terms of CAC progression, a pooled analysis of two cohort studies disclosed a significant association between increased HOMA-IR levels and CAC progression, with an OR of 1.44 (95% CI: 1.04-2.01, I2 = 21%, P < 0.05). It is important to note that the strength of the evidence was rated as low for the prevalence of CAC and very low for the progression of CAC.

Conclusion

There is evidence to suggest that a relatively high HOMA-IR may be linked with an increased prevalence and progression of CAC.

The clinical value of glycosylated hemoglobin level in newly diagnosed ketosis-prone type 2 diabetes

Objective

To evaluate the clinical value of glycosylated hemoglobin (HbA1c) in newly diagnosed ketosis-prone type 2 diabetes (KPD).

Methods

A total of 330 patients with newly diagnosed type 2 diabetes (T2DM) hospitalized in our department with an average age of 48.72 ± 13.07 years old were selected and divided into T2DM group (193 cases) and KPD group (137 cases) according to whether they were combined with ketosis. According to the quartile level of HbA1c, they were divided into group A (HbA1c < 8.90%, 84 cases), group B (8.90%≤HbA1c < 10.70%, 86 cases), group C (10.70%≤HbA1c ≤ 12.40%, 85 cases) and group D (HbA1c > 12.40%, 75 cases). The general clinical features, laboratory indicators and islet function of each group were compared. Spearman correlation analysis was used to explore the correlation between HbA1c and β- Hydroxybutyric acid (β- HB) and islet function. ROC curve was used to analyze the sensitivity and specificity of HbA1c in diagnosing KPD, and the optimal tangent point was obtained.

Results

HbA1c, β-HB, FFA, RBG, insulin dosage, GSP, OGTT (0, 0.5, 1, 2, 3h) in KPD group were significantly higher than those in T2DM group (P< 0.001). HDL-C, IRT (0, 0.5, 1, 2, 3h), HOMA-β, HOMA-IR, HOMA-IS, ΔC30/ΔG30, AUC insulin were significantly lower than those in T2DM group (P< 0.001). With the increase of HbA1c level, the incidence of ketosis, β-HB, FFA and insulin dosage increased, while IRT (0, 0.5, 1, 2, 3h), ΔC30/ΔG30, AUC insulin, HOMA-β and HOMA-IS decreased accordingly (P< 0.001). In all newly diagnosed T2DM patients, Spearman correlation analysis showed that HbA1c was positively correlated with β-HB (r=0.539, P < 0.001), and was negatively correlated with HOMA-β (r=-0.564, P < 0.001), HOMA-IS (r=-0.517, P < 0.01, P < 0.001), HOMA-IR (r=-0.177, P < 0.001), ΔC30/ΔG30 (r=-0.427, P < 0.01) and AUC insulin (r=-0.581, P < 0.001). In ROC curve analysis, the optimal threshold for the diagnosis of KPD was 10.15%, Youden index was 0.616, area under the curve (AUC) was 0.882, sensitivity = 92.70%, specificity = 70.50%.

Conclusion

In newly diagnosed T2DM patients, if HbA1c > 10.15%, it is more likely to develop KPD. Monitoring HbA1c level is conducive to timely detection of high-risk individuals with KPD and taking appropriate measures to prevent the occurrence and development of the disease.

The association between glycosylated haemoglobin and newly diagnosed hypertension in a non-diabetic Sudanese population: a cross-sectional study

BACKGROUND

Glycosylated haemoglobin (HbA1c) is considered reliable for diagnosing and monitoring diabetes mellitus (DM). It also indicates cardiovascular complications related to DM. However, only a few studies have been conducted on this topic.

METHODS

We conducted a cross-sectional study to investigate the association between newly diagnosed hypertension and HbA1c among non-diabetic Sudanese adults. The sociodemographic characteristics of the participants in the sample were gathered using a questionnaire, and HbA1c was measured using an Ichroma machine.

RESULTS

Three hundred and eighty-four healthy participants were enrolled in this study. The median (interquartile range [IQR]) age was 56.0 (14.0) years, and 72.1% of the participants were female. The median (IQR) body mass index (BMI) was 31.2 (8.7) kg/m². One hundred and fifteen (29.9%) participants presented newly diagnosed hypertension. The results of the multivariate analysis showed that age (adjusted odd ratio [AOR] = 1.03; 95% confidence interval [CI] = 1.01‒1.05); BMI (AOR = 1.09; 95% CI = 1.05‒1.14); HbA1c levels (AOR = 2.18; 95% CI = 1.29‒3.67) was positively associated with newly diagnosed hypertension. For an HbA1c level of 5.0% or more, the sensitivity and specificity of newly diagnosed hypertension were 91.3% and 28.2%, respectively (area under the curve = 0.61; 95% CI = 0.55-0.67; P ˂ 0.001). Participants who presented HbA1c levels of 5.0% or more were found to be at higher risk for newly diagnosed hypertension (AOR = 2.53; 95% CI = 1.14‒5.61).

CONCLUSION

The results of this study indicated a high prevalence of newly diagnosed hypertension, and HbA1c levels were positively associated with newly diagnosed hypertension.

Influence of sex and menopausal status on the relationship between metabolic syndrome and coronary artery calcification: a Chinese community-based cross-sectional study

OBJECTIVE

To evaluate the association between metabolic syndrome and coronary artery calcification according to different sex and menopausal status.

METHODS

This cross-sectional study included 2,704 adults from the Jidong community (Tangshan, China) recruited from July 2013 to August 2014. Adults aged ≥40 years with no cardiovascular disease and with coronary artery calcification score data were included. Metabolic syndrome was defined according to the 2005 International Diabetes Federation standard. Coronary artery calcification score was determined using the Agatston method. The associations between metabolic syndrome and coronary artery calcification prevalence were evaluated using logistic regression.

RESULTS

In the multivariable regression analysis, metabolic syndrome was associated with coronary artery calcification (odds ratio: 1.34, 95% confidence interval: 1.04-1.71, P = 0.021). When stratified by sex, metabolic syndrome was positively associated with coronary artery calcification prevalence in female participants (odds ratio: 2.79, 95% confidence interval: 1.96-3.96, P < 0.001), whereas no association was observed in male participants. Furthermore, metabolic syndrome was associated with a higher prevalence of coronary artery calcification (P < 0.001) independent of adjustment for covariates in postmenopausal women than in premenopausal women, and coronary artery calcification prevalence increased with an increase in conditions related to metabolic syndrome.

CONCLUSIONS

Our findings indicate that metabolic syndrome in postmenopausal women is associated with a higher prevalence of coronary artery disease than in premenopausal women and men.

[Mönkeberg's sclerosis: role of calcification in arterial lesions in patients with diabetes mellitus]

The number of patients with diabetes mellitus has steadily been increasing. This disease is associated with the risk for the development of micro- and macroangiopathies. One of the variants of macroangiopathy is Mönkeberg's sclerosis characterized by the presence of calcification of the media of the arterial wall. This article is a literature review reflecting the role of calcification in arterial lesions in patients with diabetes mellitus, also covering the historical aspect of studying Mönkeberg's sclerosis. Special attention is paid to its morphological forms, aetiopathogenetic mechanisms of development, taking into account contemporary studies, demonstrating mechanisms of the effect of medial arterial calcification on haemodynamics and the risk for the development of cardiovascular complications. Also presented herein are the main non-invasive and invasive methods of its diagnosis.

Elevated glycosylated hemoglobin levels and their interactive effects on hypertension risk in nondiabetic Chinese population: a cross-sectional survey

BACKGROUND

Abnormal glucose metabolism has been suggested to be involved in the development of hypertension. This study investigated the effect of the association and potential interaction of glycosylated hemoglobin (HbA1c) and other factors on the risk of hypertension among Chinese nondiabetic adults.

METHODS

As a cross-sectional survey, the current work deployed a questionnaire survey, anthropometric tests, and biochemical measures for each of the eligible participants. The HbA1c levels were quantified and grouped by quartiles. Correlations between HbA1c and hypertension, isolated systolic hypertension (ISH), and isolated diastolic hypertension (IDH) risk were investigated by logistic analyses. For evaluating the interactive effects, the parameters of relative excess risk due to interaction (RERI), attributable proportion due to interaction (AP), and synergy index (SI) were calculated, respectively.

RESULTS

In the current study, 1462 nondiabetic subjects were enrolled. In total, the prevalence rates of hypertension, ISH and IDH were 22.4, 9.6 and 4.5%, respectively. When HbA1c levels were grouped by quartile, it was revealed that the prevalence rates of hypertension and ISH were substantially elevated across groups (Pfor trend < 0.001). In the multivariable logistic regression analyses, in comparison with the first quartile of HbA1c, the normalized OR for hypertension risk was 1.90 (95% CI: 1.28-2.80) for the highest quartile. Also, the risk of ISH was significantly increased with HbA1c level in the highest quartile relative to in the bottom quartile (OR: 2.23,95% CI:1.47-3.71). However, no significant relationship between the HbA1c level and IDH risk was observed (OR: 1.78, 95% CI: 0.82-3.84). Eventually, it was demonstrated from the interactive effect analysis that HbA1c significantly interacted with abdominal obesity (RERI: 1.48, 95% CI: 0.38-2.58; AP: 0.37, 95% CI: 0.14-0.60 and SI: 1.96, 95% CI: 1.06-3.62) and family history of hypertension (AP: 0.37, 95% CI: 0.05-0.70) in influencing the risk of hypertension in nondiabetic participants.

CONCLUSION

Higher HbA1c levels significantly enhanced the risk of hypertension and ISH, but not IDH among Chinese nondiabetic adults. Moreover, the risk of hypertension was also aggravated by the upregulated HbA1c in a synergistic manner alongside abdominal obesity and family history of hypertension.

Association between metformin use and below-the-knee arterial calcification score in type 2 diabetic patients

Background

Vascular calcification (VC) is common in type 2 diabetes, and is associated with cardiovascular complications. Recent preclinical data suggest that metformin inhibits VC both in vitro and in animal models. However, metformin’s effects in patients with diabetic VC have not previously been characterized. The present study investigated the association between metformin use and lower-limb arterial calcification in patients with type 2 diabetes and high cardiovascular risk.

Methods

The DIACART cross-sectional cohort study included 198 patients with type 2 diabetes but without severe chronic kidney disease. Below-the-knee calcification scores were assessed by computed tomography and supplemented by colour duplex ultrasonography. Data on anti-diabetic drugs were carefully collected from the patients’ medical records and during patient interviews. Biochemical and clinical data were studied as potential confounding factors.

Results

Metformin-treated patients had a significantly lower calcification score than metformin-free patients (mean ± standard deviation: 2033 ± 4514 and 4684 ± 9291, respectively; p = 0.01). A univariate analysis showed that metformin was associated with a significantly lower prevalence of severe below-the-knee arterial calcification (p = 0.02). VC was not significantly associated with the use of other antidiabetic drugs, including sulfonylureas, insulin, gliptin, and glucagon like peptide-1 analogues. A multivariate logistic regression analysis indicated that the association between metformin use and calcification score (odds ratio [95% confidence interval] = 0.33 [0.11–0.98]; p = 0.045) was independent of age, gender, tobacco use, renal function, previous cardiovascular disease, diabetes duration, neuropathy, retinopathy, HbA_1c levels, and inflammation.

Conclusions

In patients with type 2 diabetes, metformin use was independently associated with a lower below-the-knee arterial calcification score. This association may contribute to metformin’s well-known vascular protective effect. Further prospective investigations of metformin’s potential ability to inhibit VC in patients with and without type 2 diabetes are now needed to confirm these results.

Pathology of Human Coronary and Carotid Artery Atherosclerosis and Vascular Calcification in Diabetes Mellitus

The continuing increase in the prevalence of diabetes mellitus in the general population is predicted to result in a higher incidence of cardiovascular disease. Although the mechanisms of diabetes mellitus-associated progression of atherosclerosis are not fully understood, at clinical and pathological levels, there is an appreciation of increased disease burden and higher levels of arterial calcification in these subjects. Plaques within the coronary arteries of patients with diabetes mellitus generally exhibit larger necrotic cores and significantly greater inflammation consisting mainly of macrophages and T lymphocytes relative to patients without diabetes mellitus. Moreover, there is a higher incidence of healed plaque ruptures and positive remodeling in hearts from subjects with type 1 diabetes mellitus and type 2 diabetes mellitus, suggesting a more active atherogenic process. Lesion calcification in the coronary, carotid, and other arterial beds is also more extensive. Although the role of coronary artery calcification in identifying cardiovascular disease and predicting its outcome is undeniable, our understanding of how key hormonal and physiological alterations associated with diabetes mellitus such as insulin resistance and hyperglycemia influence the process of vascular calcification continues to grow. Important drivers of atherosclerotic calcification in diabetes mellitus include oxidative stress, endothelial dysfunction, alterations in mineral metabolism, increased inflammatory cytokine production, and release of osteoprogenitor cells from the marrow into the circulation. Our review will focus on the pathophysiology of type 1 diabetes mellitus- and type 2 diabetes mellitus-associated vascular disease with particular focus on coronary and carotid atherosclerotic calcification.

Glycated Hemoglobin is a Better Predictor than Fasting Glucose for Cardiometabolic Risk in Non-diabetic Korean Women

This study aimed to investigate if glycated hemoglobin (Hgb_A1C) as compared to fasting blood glucose is better for reflecting cardiometabolic risk in non-diabetic Korean women. Fasting glucose, Hgb_A1C and lipid profiles were measured in non-diabetic women without disease (n = 91). The relationships of fasting glucose or Hgb_A1C with anthropometric parameters, lipid profiles, and liver and kidney functions were analyzed. Both fasting glucose and Hgb_A1C were negatively correlated with HDL-cholesterol (r = -0.287, p = 0.006; r = -0.261, p = 0.012), and positively correlated with age (r = 0.202, p = 0.008; r = 0.221, p = 0.035), waist circumference (r = 0.296, p = 0.005; r = 0.304, p = 0.004), diastolic blood pressure (DBP) (r = 0.206, p = 0.050; r = 0.225, p = 0.032), aspartate transaminase (AST) (r = 0.237, p = 0.024; r = 0.368, p < 0.0001), alanine transaminase (ALT) (r = 0.296, p = 0.004; r = 0.356, p = 0.001), lipid profiles including triglyceride (r = 0.372, p < 0.001; r = 0.208, p = 0.008), LDL-cholesterol (r = 0.315, p = 0.002; r = 0.373, p < 0.0001) and total cholesterol (r = 0.310, p = 0.003; r = 0.284, p = 0.006). When adjusted for age and body mass index, significant relationships of DBP (r = 0.190, p = 0.049), AST (r = 0.262, p = 0.018), ALT (r = 0.277, p = 0.012), and HDL-cholesterol (r = -0.202, p = 0.049) with Hgb_A1C were still retained, but those with fasting glucose disappeared. In addition, the adjusted relationships of LDL-cholesterol and total cholesterol with Hgb_A1C were much greater than those with fasting glucose. These results suggest that glycated hemoglobin may be a better predictor than fasting glucose for cardiometabolic risk in non-diabetic Korean women.