Abdominal Aortic Calcification Among Individuals With and Without Diabetes: The Jackson Heart Study

Association between hemoglobin A1c and abdominal aortic calcification: results from the National Health and Nutrition Examination Survey 2013-2014

BACKGROUND

Hemoglobin A1c (HbA1c), a "gold standard" for the assessment of glycemic control, was associated with an increased risk of cardiovascular disease and coronary artery calcification. However, its effects on abdominal aortic calcification (AAC) are uncertain. The present study comprehensively investigated the association between HbA1c and AAC in the 2013-2014 National Health and Nutrition Examinations Surveys.

METHODS

Among 1,799 participants ≥ 40 years, dual-energy X-ray absorptiometry-derived AAC was quantified using the Kauppila score (AAC-24). Severe AAC was defined as a total AAC-24 > 6. Weighted linear regression models and logistic regression models were used to determine the effects of HbA1c on AAC. The restricted cubic spline model was used for the dose-response analysis.

RESULTS

The mean AAC-24 of participants was 1.3, and 6.7% of them suffered from severe AAC. Both AAC-24 and the prevalence of severe AAC increased with the higher tertile of HbA1c (P < 0.001). Elevated HbA1c levels would increase the AAC-24 (β = 0.73, 95% CI: 0.30-1.16) and the risk of severe AAC (OR = 1.63, 95% CI: 1.29-2.06), resulting in nearly linear dose-response relationships in all participants. However, this positive correlation were not statistically significant when participants with diabetes were excluded. Furthermore, subgroup analysis showed significant interactions effect between HbA1c and hypertension on severe AAC with the OR (95% CI) of 2.35 (1.62-3.40) for normotensives and 1.39 (1.09-1.79) for hypertensives (P for interaction = 0.022).

CONCLUSION

Controlling HbA1c could reduce AAC scores and the risk of severe AAC. Glycemic management might be a component of strategies for preventing AAC among all participants, especially normotensives.

The association of moderate-to-vigorous physical activity and sedentary behaviour with abdominal aortic calcification

BACKGROUND AND AIMS

The increasing prevalence of metabolic and cardiovascular diseases poses a significant challenge to global healthcare systems. Regular physical activity (PA) is recognized for its positive impact on cardiovascular risk factors. This study aimed to investigate the relationship between moderate-to-vigorous physical activity (MVPA), sedentary behavior (SB), and abdominal aortic calcification (AAC) using data from the National Health and Nutrition Examination Survey (NHANES).

METHODS

The study used data from NHANES participants aged 40 and above during the 2013-2014 cycle. AAC scores were assessed using the Kauppila scoring system, and MVPA and SB were self-reported. Sociodemographic variables were considered, and multivariable linear regression models were used to analyze associations between MVPA, SB, and AAC scores. Subgroup analyses were conducted based on age, sex, BMI, hypertension, and diabetes.

RESULTS

The study included 2843 participants. AAC prevalence was higher in older age groups, smokers, and those with diabetes or hypertension. Lower socioeconomic status was associated with higher AAC prevalence. Individuals engaged in any level of MVPA exhibited lower AAC rates compared to inactive individuals. Not engaging in occupational MVPA (β = 0.46, 95% confidence interval = 0.24‒0.67, p < .001) and prolonged SB (β = 0.28, 95% confidence interval = 0.04‒0.52, p = .023) were associated with higher AAC scores. However, no significant associations were found for transportation and leisure time MVPA. Subgroup analysis revealed age and hypertension as effect modifiers in the MVPA-AAC relationship.

CONCLUSIONS

This study highlights the potential benefits of engaging in occupational MVPA and reducing SB in mitigating AAC scores, particularly among older individuals and those with hypertension.

The association between weight-adjusted-waist index and abdominal aortic calcification in adults aged ≥ 40 years: results from NHANES 2013-2014

The negative effects of obesity on the cardiovascular health have drawn much attention. Weight-adjusted-waist index (WWI) has been proved to reflect weight-independent centripetal obesity. However, the association between WWI and abdominal aortic calcification (AAC) has not been reported before. Using data from National Health and Nutrition Examination Survey 2013-2014, we aimed to determine the relationship of WWI and AAC in adults aged ≥ 40 years. WWI was determined by dividing waist circumference by the square root of weight. AAC was measured by dual-energy X-ray absorptiometry and quantified by Kauppila scores. Severe AAC (SAAC) was defined as an AAC score > 6. We utilized weighed multivariable logistic regression and generalized additive model to explore the independent association between WWI and AAC. Threshold effects were further calculated by two-piecewise linear regression model. 3082 participants were enrolled in our analysis, of which 48.2% were male. WWI was positively associated with AAC scores (β = 0.34, 95% CI 0.05-0.63) and exhibited a nonlinear relationship with SAAC. On the left of the breakpoint (WWI = 11.11), WWI and SAAC were positively associated (OR = 2.86, 95% CI 1.40-5.84), while no such relationship was found on the right (OR = 1.07, 95% CI 0.77-1.48). Our findings indicated that WWI may serve as a simple biomarker of AAC in US adults aged ≥ 40 years.

Abdominal aortic calcification is associated with Fib-4 index and low body mass index in type 2 diabetes: a retrospective cross-sectional study

AIMS

This study aimed to clarify the nature of the relationship between the abdominal aortic calcification (AAC) grade and the presence of cardiovascular diseases and determine factors related to AAC grade in participants with type 2 diabetes (T2DM).

METHODS

This retrospective cross-sectional study enrolled 264 in participants with T2DM. The AAC score and length were measured using the lateral abdominal radiographs. Logistic regression models were used to assess the associations between AAC scores/lengths and the presence of coronary artery disease (CAD), cerebral infarction (CI), and peripheral artery disease (PAD). The correlation between AAC scores/lengths and other clinical factors were evaluated using linear regression models.

RESULTS

The AAC score was significantly correlated with prevalent CAD and CI independent of age and smoking but not with the prevalence of PAD. AAC length was not significantly correlated with the presence of CAD, CI, or PAD; however, the sample size was insufficient to conclude probably due to low prevalence. Both the AAC score and length were correlated inversely with body mass index (BMI) and, with the Fib-4 index >2.67; these correlations were significant after adjusting for cardiovascular risk factors and BMI, although AAC was not associated with ultrasonography-diagnosed fatty liver. There was a significant interaction between BMI and Fib-4 index; lower BMI and Fib-4 index >2.67 demonstrated a synergistic association with high AAC grade.

CONCLUSIONS

AAC score is associated with CAD and CI morbidity in participants with T2DM. Low BMI and Fib-4 index >2.67 can be valuable indicators of AAC in people with T2DM.

Prevalence and risk factors for the development of abdominal aortic calcification among the US population: NHANES study

Introduction

Abdominal aortic calcification (AAC) is an important marker of subclinical cardiovascular disease and its prognosis. Advanced age, hypertension, smoking, dyslipidemia, diabetes mellitus, and higher truncal fat are known markers of AAC in studies conducted around the world. However, literature for these risk factors and their co-occurrence is limited in the US.

Material and methods

We used data from dual energy X-ray absorptiometry (Hologic, v4.0) to detect the occurrence of AAC in a sample population (n = 3140) of the NHANES survey using a computer-assisted interviewing system to assess the risk factors for AAC.

Results

We found the national prevalence of AAC in the US to be 28.8%. After adjusting for confounders, persons with hypertension: OR = 1.66 (95% CI: 1.30–2.13) and smokers: OR = 1.63 (95% CI: 1.24–2.14) were more likely to have AAC compared to their respective counterparts. Increasing age was positively associated with AAC: OR = 1.06 (95% CI: 1.04–1.08). There was a statistically significant negative association between body mass index (BMI) and AAC, more so in smokers than in non-smokers: OR = 0.97 (95% CI: 0.94–0.97). We did not observe any statistically significant association between diabetes and AAC.

Conclusions

Advanced age, smoking, and hypertension was associated with increased occurrence of AAC. Paradoxically, increasing BMI was inversely associated with AAC and there was no statistically significant association between total body and trunk fat percentages and AAC. To the best of our knowledge, this is the first study to establish the nationwide prevalence and associated factors in the US.

Arterial endothelial function, carotid artery intima-media thickness and abdominal aortic calcification in diabetic and nondiabetic CKD stage 4-5 patients not on dialysis

AIMS

We aimed to study the effect of diabetes (DM) on endothelial dysfunction assessed by flow-mediated vasodilatation (FMD), carotid intima-media thickness (cIMT) and abdominal aortic calcification score (AAC) in chronic kidney disease (CKD) stage 4-5 patients not on dialysis.

METHODS

Altogether 199 non-dialysis CKD stage 4-5 patients enrolled in the Chronic Arterial Disease, quality of life and mortality in chronic KIDney injury (CADKID) study with plain lumbar radiograph for the assessment of AAC were included. Data on cIMT and FMD were available for 172 and 161 patients, respectively.

RESULTS

Median age was 65 (IQR 54-76) years, 88 (44.2%) patients had DM and median eGFR was 12 (IQR 10-14) ml/min/1.73 m² in the study. FMD [controls: 3.3(2.0-6.7)% vs. DM-patients: 4.3(1.3-6.6)%, p = 0.73] and cIMT [controls: 0.65(0.58-0.87)mm vs. DM-patients: 0.67(0.59-0.81)mm, p = 0.65], were similar between the groups. AAC was higher in patients with DM [controls: 5(1-9) vs. DM-patients: 7(2-13), p = 0.01]. The significant multivariate determinants for AAC were older age (β = 0.22, p < 0.0001), pulse pressure (β = 0.05, p < 0.0001), DM (β = 1.33, p = 0.04) and ProBNP (per µg/l β = 0.18, p = 0.0008). AAC and cIMT were associated with incident cardiovascular death independent of DM.

CONCLUSIONS

DM is associated with increased AAC but not increased cIMT or attenuated FMD in advanced CKD patients.

Aberration methylation of miR-34b was involved in regulating vascular calcification by targeting Notch1

Vascular calcification is one of the most important factors for cardiovascular and all-cause mortality in patients with end-stage renal diseases (ESRD). The current study was aimed to investigate the function and mechanisms of miR-34b on the calcification of vascular smooth muscle cells (VSMCs) both in vitro and in vivo. We found that the expression of miR-34b was significantly suppressed in VSMCs with high inorganic phosphate (Pi) treatment, as well as mouse arteries derived from 5/6 nephrectomy with a high-phosphate diet (0.9% Pi, 5/6 NTP) and human renal arteries from uraemia patients. Overexpression of miR-34b alleviated calcification of VSMCs, while VSMCs calcification was enhanced by inhibiting the expression of miR-34b. Bisulphite sequencing PCR (BSP) uncovered that CpG sites upstream of miR-34b DNA were hypermethylated in calcified VSMCs and calcified arteries due to 5/6 NTP, as well as calcified renal arterial tissues from uraemia patients. Meantime, increased DNA methyltransferase 3a (DNMT3a) resulted in the hypermethylation of miR-34b in VSMCs, while 5-aza-2′-deoxycytidine (5-aza) reduced the methylation rate of miR-34b and restored the expression of miR-34b in VSMCs. When DNMT3a was knocked down using DNMT3a siRNA, the effect of 3.5 mM of Pi on calcification of VSMCs was abrogated. In addition, Notch1 was validated as the functional target of miR-34b and involved in the process of calcification of VSMCs. Taken together, our data showed a specific role for miR-34b in regulating calcification of VSMCs both in vitro and in vivo, which was regulated by upstream DNA methylation of miR-34b and modulated by the downstream target gene expression, Notch1. These results suggested that modulation of miR-34b may offer new insight into a novel therapeutic approach for vascular calcification.