Arterial location-specific calcification at the carotid artery and aortic arch for chronic kidney disease, diabetes mellitus, hypertension, and dyslipidemia

Chest radiography as a biomarker of ageing: artificial intelligence-based, multi-institutional model development and validation in Japan

BACKGROUND

Chest radiographs are widely available and cost-effective; however, their usefulness as a biomarker of ageing using multi-institutional data remains underexplored. The aim of this study was to develop a biomarker of ageing from chest radiography and examine the correlation between the biomarker and diseases.

METHODS

In this retrospective, multi-institutional study, we trained, tuned, and externally tested an artificial intelligence (AI) model to estimate the age of healthy individuals using chest radiographs as a biomarker. For the biomarker modelling phase of the study, we used healthy chest radiographs consecutively collected between May 22, 2008, and Dec 28, 2021, from three institutions in Japan. Data from two institutions were used for training, tuning, and internal testing, and data from the third institution were used for external testing. To evaluate the performance of the AI model in estimating ages, we calculated the correlation coefficient, mean square error, root mean square error, and mean absolute error. The correlation investigation phase of the study included chest radiographs from individuals with a known disease that were consecutively collected between Jan 1, 2018, and Dec 31, 2021, from an additional two institutions in Japan. We investigated the odds ratios (ORs) for various diseases given the difference between the AI-estimated age and chronological age (ie, the difference-age).

FINDINGS

We included 101 296 chest radiographs from 70 248 participants across five institutions. In the biomarker modelling phase, the external test dataset from 3467 healthy participants included 8046 radiographs. Between the AI-estimated age and chronological age, the correlation coefficient was 0·95 (99% CI 0·95-0·95), the mean square error was 15·0 years (99% CI 14·0-15·0), the root mean square error was 3·8 years (99% CI 3·8-3·9), and the mean absolute error was 3·0 years (99% CI 3·0-3·1). In the correlation investigation phase, the external test datasets from 34 197 participants with a known disease included 34 197 radiographs. The ORs for difference-age were as follows: 1·04 (99% CI 1·04-1·05) for hypertension; 1·02 (1·01-1·03) for hyperuricaemia; 1·05 (1·03-1·06) for chronic obstructive pulmonary disease; 1·08 (1·06-1·09) for interstitial lung disease; 1·05 (1·03-1·06) for chronic renal failure; 1·04 (1·03-1·06) for atrial fibrillation; 1·03 (1·02-1·04) for osteoporosis; and 1·05 (1·03-1·06) for liver cirrhosis.

INTERPRETATION

The AI-estimated age using chest radiographs showed a strong correlation with chronological age in the healthy cohorts. Furthermore, in cohorts of individuals with known diseases, the difference between estimated age and chronological age correlated with various chronic diseases. The use of this biomarker might pave the way for enhanced risk stratification methodologies, individualised therapeutic interventions, and innovative early diagnostic and preventive approaches towards age-associated pathologies.

FUNDING

None.

TRANSLATION

For the Japanese translation of the abstract see Supplementary Materials section.

Aortic calcification is associated with coronary artery calcification and is a potential surrogate marker for ischemic heart disease risk: A cross-sectional study

Coronary artery calcification, an established marker of atherosclerotic plaque burden associated with increased risk of coronary artery disease, is routinely evaluated using electron beam computerized tomography or multidetector computed tomography (CT). However, aortic calcification, which is also a risk factor for adverse cardiac events, is not frequently assessed, despite being easily detected via standard chest radiography. We therefore sought to clarify the association between aortic calcification and significant coronary artery calcification to determine the feasibility of performing chest radiography to evaluate the risk of future cardiovascular events. Data from 682 consecutive patients who underwent cardiac CT scanning at our institution from May to September 2012 were included in this cross-sectional analysis. Electrocardiographic-gated CT was used to qualitatively evaluate calcification in 6 aortic segments. Cardiac contrast-ehnanced CT was performed to identify significant calcification of the coronary artery. Calcification was quantified by calculating the Agatston score, and the relationship between significant coronary artery calcification and calcification at each aortic site was evaluated. Among the aortic sites, calcification was most commonly observed in the aortic arch (77.4% of patients). Significant coronary artery calcification was observed in 267 patients (39.1%). Calcification in the ascending aorta, aortic arch, descending aorta, abdominal aorta, and aortic valve were significantly associated with the presence of coronary artery calcification after adjustment for cardiovascular risk factors and statin use (odds ratios [95% confidence intervals] 4.21 [2.55, 6.93], 1.65 [1.01, 2.69], 2.14 [1.36, 3.36], 2.87 [1.83, 4.50], and 3.32 [2.02, 5.46], respectively). Mitral valve calcification was weakly but nonsignificantly associated with coronary artery calcification (odds ratio 1.84 [95% confidence interval 0.94, 3.62]). Calcification of each aortic segment assessed was significantly associated with Agatston score ≥ 100. Aortic calcification was associated with coronary artery calcification. Calcification of the aortic arch, which can be readily detected by routine chest radiography, may be associated with coronary artery calcification and its assessment should therefore be considered to identify patients at increased risk of cardiovascular events. Further studies are warranted to confirm these findings.

Combining phosphate binder therapy with vitamin K2 inhibits vascular calcification in an experimental animal model of kidney failure

BACKGROUND

Hyperphosphataemia is strongly associated with cardiovascular disease and mortality. Recently, phosphate binders (PBs), which are used to bind intestinal phosphate, have been shown to bind vitamin K, thereby potentially aggravating vitamin K deficiency. This vitamin K binding by PBs may offset the beneficial effects of phosphate reduction in reducing vascular calcification (VC). Here we assessed whether combining PBs with vitamin K2 supplementation inhibits VC.

METHODS

We performed 3/4 nephrectomy in rats, after which warfarin was given for 3 weeks to induce vitamin K deficiency. Next, animals were fed a high phosphate diet in the presence of low or high vitamin K2 and were randomized to either control or one of four different PBs for 8 weeks. The primary outcome was the amount of thoracic and abdominal aorta VC measured by high-resolution micro-computed tomography (µCT). Vitamin K status was measured by plasma MK7 levels and immunohistochemically analysed in vasculature using uncarboxylated matrix Gla protein (ucMGP) specific antibodies.

RESULTS

The combination of a high vitamin K2 diet and PB treatment significantly reduced VC as measured by µCT for both the thoracic (P = 0.026) and abdominal aorta (P = 0.023), compared with MK7 or PB treatment alone. UcMGP stain was significantly more present in the low vitamin K2-treated groups in both the thoracic (P < 0.01) and abdominal aorta (P < 0.01) as compared with high vitamin K2-treated groups. Moreover, a high vitamin K diet and PBs led to reduced vascular oxidative stress.

CONCLUSION

In an animal model of kidney failure with vitamin K deficiency, neither PB therapy nor vitamin K2 supplementation alone prevented VC. However, the combination of high vitamin K2 with PB treatment significantly attenuated VC.

Abdominal Aortic Calcification Is a Significant Poor Prognostic Factor for Clinical Outcomes After Decompressive Laminotomy for Lumbar Spinal Canal Stenosis

STUDY DESIGN

Retrospective study.

OBJECTIVE

To examine whether the presence of chronic kidney disease (CKD) or advanced abdominal aortic calcification (AAC) negatively affects clinical outcomes after decompression surgery for lumbar spinal canal stenosis (LSCS).

METHODS

The subjects comprised 143 patients who underwent decompressive laminotomy for LSCS and were followed for ≥2 years. Fifty-five patients had CKD (Stage 3-4). Clinical outcome was assessed using the Japanese Orthopaedic Association (JOA) score before surgery and at 2-year postoperatively. According to the scoring system by Kauppila et al, the AAC score (a surrogate marker of systemic atherosclerosis) was assessed using preoperative lateral radiographs of the lumbar spine.

RESULTS

Patient age had weak but significantly negative correlations with both the preoperative JOA score and the JOA score at 2 years after surgery, but did not have a significant correlation with the recovery rate of the JOA score at 2 years postoperatively. The JOA score before surgery, the JOA score at 2-year follow-up, and the recovery rate of the JOA score were slightly lower in the CKD patients than in those without CKD, although there were no significant differences between the 2 groups. On the contrary, the AAC score had a weak but significantly negative correlation with the preoperative JOA score, and had relatively strong and significantly negative correlations with both the JOA score at 2 years after surgery and the recovery rate of the JOA score.

CONCLUSIONS

At 2 years after surgery, advanced AAC was a significant poor prognostic factor for clinical outcomes of decompression surgery for LSCS.

Aortic Arch Calcification Is a Strong Predictor of the Severity of Coronary Artery Disease in Patients with Acute Coronary Syndrome

BACKGROUND

The purpose of this study was to investigate the correlation of the extent of aortic arch calcification (AAC) detectable on chest X-rays with the severity of coronary artery disease (CAD) as evaluated by the SYNTAX score (SS) in patients with acute coronary syndrome (ACS).

METHODS

A total of 1,418 patients (344 women; 59 ± 10 years) who underwent coronary angiography for ACS and were treated with coronary revascularization were included in the present study; chest X-rays were performed on admission. The AAC extent was divided into four grades (0-3). SS was calculated based on each patient's coronary angiographic findings. The relationship between the AAC extent and SS was assessed.

RESULTS

The AAC extent was positively correlated with SS (ρ = 0.639, P < 0.001). In the multivariate analysis, compared with grade 0, odds ratios (ORs) of AAC grades 1, 2, and 3 in predicting SS >22 were 12.95 (95% CI, 7.85-21.36), 191.76 (95% CI, 103.17-356.43), and 527.81 (95% CI, 198.24-1405.28), respectively. Receiver operating characteristic curve analysis yielded a strong predictive ability of the AAC extent for SS >22 (area under curve = 0.840, P < 0.001). Absence of AAC had a sensitivity, specificity, positive prognostic value, negative prognostic value, and accuracy of 46.7%, 95.9%, 94.1%, 56.4%, and 67.3%, respectively, for SS ≤22. AAC grades ≥2 had a sensitivity of 66.3%, specificity of 89.2%, positive prognostic value of 81.5%, negative prognostic value of 78.6%, and accuracy of 79.6% for the correct identification of SS >22.

CONCLUSIONS

The extent of AAC detectable on chest X-rays might provide valuable information in predicting CAD severity in ACS patients.

Respiratory sympathetic modulation is augmented in chronic kidney disease

Respiratory modulation of sympathetic nerve activity (respSNA) was studied in a hypertensive rodent model of chronic kidney disease (CKD) using Lewis Polycystic Kidney (LPK) rats and Lewis controls. In adult animals under in vivo anaesthetised conditions (n = 8-10/strain), respiratory modulation of splanchnic and renal nerve activity was compared under control conditions, and during peripheral (hypoxia), and central, chemoreceptor (hypercapnia) challenge. RespSNA was increased in the LPK vs. Lewis (area under curve (AUC) splanchnic and renal: 8.7 ± 1.1 vs. 3.5 ± 0.5 and 10.6 ± 1.1 vs. 7.1 ± 0.2 μV.s, respectively, P < 0.05). Hypoxia and hypercapnia increased respSNA in both strains but the magnitude of the response was greater in LPK, particularly in response to hypoxia. In juvenile animals studied using a working heart brainstem preparation (n = 7-10/strain), increased respSNA was evident in the LPK (thoracic SNA, AUC: 0.86 ± 0.1 vs. 0.42 ± 0.1 μV.s, P < 0.05), and activation of peripheral chemoreceptors (NaCN) again drove a larger increase in respSNA in the LPK with no difference in the response to hypercapnia. Amplified respSNA occurs in CKD and may contribute to the development of hypertension.

Dilated Perivascular Spaces in the Centrum Semiovale Begin to Develop in Middle Age

BACKGROUND

Dilated perivascular spaces in the centrum semiovale (CSO-PVS) are closely related to small vessel disease. However, recent studies have revealed that cerebral amyloid angiopathy can cause dilation of the CSO-PVS and obstruction of interstitial fluid flow along the intramural periarterial drainage.

OBJECTIVE

To examine the severity and age-related prevalence of CSO-PVS through magnetic resonance imaging (MRI) and investigate their clinically relevant factors.

METHODS

This study included 1,060 subjects who participated in our brain program. The subjects ranged from 23 to 83 years in age and were active in society. The frequencies of the MRI abnormalities of small vessel diseases, including CSO-PVS, were examined. The CSO-PVS severity was classified into three grades: G0, G1, G2, according to the visual rating. The subjects were divided into five age groups and their age-related frequencies were also studied. Using the clinico-laboratory data of 712 subjects, the clinically relevant factors of CSO-PVS were investigated using logistic regression analysis.

RESULTS

The frequencies of all G0 ("normal") MRI abnormalities significantly decreased with age. A high prevalence of G2 CSO-PVS was observed (24%) in the youngest group aged≤39 years, whereas other MRI abnormalities in this group were not or rarely observed. In multivariable logistic regression analyses, G2 CSO-PVS was found to be closely associated with age, hypertension, and the estimated glomerular filtration ratio.

CONCLUSIONS

This study reveals that CSO-PVS begin to develop in subjects aged less than 39 years. Age-related changes are involved. Further studies are necessary to elucidate the pathophysiological role of the CSO-PVS.

Energy-Dense Diets and Mineral Metabolism in the Context of Chronic Kidney Disease⁻Metabolic Bone Disease (CKD-MBD)

The aim of this paper is to review current knowledge about the interactions of energy-dense diets and mineral metabolism in the context of chronic kidney disease–metabolic bone disease (CKD-MBD). Energy dense-diets promote obesity and type II diabetes, two well-known causes of CKD. Conversely, these diets may help to prevent weight loss, which is associated with increased mortality in advanced CKD patients. Recent evidence indicates that, in addition to its nephrotoxic potential, energy-dense food promotes changes in mineral metabolism that are clearly detrimental in the context of CKD-MBD, such as phosphorus (P) retention, increased concentrations of fibroblast growth factor 23, decreased levels of renal klotho, and reduction in circulating concentrations of calcitriol. Moreover, in uremic animals, a high fat diet induces oxidative stress that potentiates high P-induced vascular calcification, and these extraskeletal calcifications can be ameliorated by oral supplementation of vitamin E. In conclusion, although energy-dense foods may have a role in preventing undernutrition and weight loss in a small section of the CKD population, in general, they should be discouraged in patients with renal disease, due to their impact on P load and oxidative stress.

Osteoprotegerin Is the Strongest Predictor for Progression of Arterial Calcification in Peritoneal Dialysis Patients

BACKGROUND

Arterial calcification (AC) is frequent in patients with end stage renal disease and is also considered a risk factor for later morbidity and mortality. However, long-term factors associated with the process are not well known. We analyzed the trends over time of biomarkers related with development and progression of AC in incident patients on peritoneal dialysis (PD).

METHODS

We performed a prospective study with 186 patients on PD followed up for 1 year. We analyzed the progression of AC in the abdominal aorta and pelvic vessels by calcification score (CaSc), using16-cut computerized multidetector tomography at baseline and 1 year. Variables related with PD treatment, inflammation, and mineral metabolism were measured at baseline, 6, and 12 months of follow-up. Changes in biochemical variables were analyzed for their relationship with changes in AC.

RESULTS

Over 1 year, the number of patients with AC increased from 47 to 56%, and CaSc from 355 (interquartile range [IQR] 75-792) to 529 (IQR 185-1632). A total of 43.5% of patients remained free of calcification, 11.7% had new calcifications, and 44.8% had progression of calcification. Older age, diabetes, high systolic blood pressure, body mass index, cholesterol, and osteoprotegerin (OPG), as well as lower levels of albumin, serum creatinine, and osteocalcin, were associated with development of new, and rapid progression of, calcification. In multivariate logistic analysis, OPG remained the most significant (OR 1.27, 95% CI 1.11-1.47, p < 0.001).

CONCLUSION

OPG was the strongest risk factor associated with new development and rapid progression of AC in incident PD patients.

Surgical outcomes after laminoplasty for cervical spondylotic myelopathy in patients with renal dysfunction and/or aortic arch calcification

OBJECTIVE The authors recently reported that the presence of chronic kidney disease (CKD) and/or extended abdominal aortic calcification was associated with significantly worse clinical outcomes after posterior lumbar interbody fusion. CKD is one of the highest risk factors for systemic atherosclerosis. Therefore, impaired blood flow due to atherosclerosis could exacerbate degeneration of the cervical spine and neural tissue. However, there has been no report of a study evaluating the deleterious effects of CKD and atherosclerosis on the outcomes after decompression surgery for cervical compression myelopathy. The purpose of this study was thus to examine whether CKD and systemic atherosclerosis affect surgical outcomes after laminoplasty for cervical spondylotic myelopathy (CSM). METHODS The authors analyzed data from 127 consecutive cases involving patients who underwent laminoplasty for CSM and met their inclusion criteria. Stage 3-4 CKD was present as a preoperative comorbidity in 44 cases. Clinical status was assessed using the Japanese Orthopaedic Association (JOA) cervical myelopathy evaluation questionnaire before surgery and 2 years postoperatively. As a marker of systemic atherosclerosis, the presence of aortic arch calcification (AoAC) was assessed on preoperative chest radiographs. RESULTS AoAC was found on preoperative chest radiographs in 40 of 127 patients. Neither CKD nor AoAC had a statistically significant deleterious effect on preoperative JOA score. However, CKD and AoAC were significantly associated with reductions in both the JOA score recovery rate (mean 36.1% in patients with CKD vs 44.7% in those without CKD; 26.0% in patients with AoAC vs 48.9% in those without AoAC) and the change in JOA score at 2 years after surgery (mean 2.3 points in patients with CKD vs 3.1 points in those without CKD; 2.1 points for patients with AoAC vs 3.2 points for those without AoAC). A multivariate regression analysis showed that AoAC was a significant independent predictor of poor outcome with respect to both for the difference between follow-up and preoperative JOA scores and the JOA score recovery rate. CONCLUSIONS CKD and AoAC were associated with increased rates of poor neurological outcomes after laminoplasty for CSM, and AoAC was a significant independent predictive factor for poor outcome.

Role of osteoprotegerin in vascular disorders of the end-stage renal disease patients

AIM

To assess the osteoprotegerin (OPG) relationship with cardiovascular complications in hemodialysis (HD) patients.

METHODS

The study included 87 HD patients. Clinical characteristics, ankle-arm index (AAI), OPG and mineral markers levels were recorded. Arterial intimal calcification (AIC) and arterial medial calcification (AMC) were registered.

RESULTS

OPG levels were increased in HD patients. Patients with AIC (p = 0.006)/ AMC (p = 0.01) had higher OPG levels. OPG did not have any relation with cardiovascular diseases. OPG correlated positively with age, increased HD vintage and inversely with albumin and AAI. OPG has not been a risk factor for VC or cardiovascular disease.

CONCLUSION

OPG rising could be a reaction in defense to vascular aggression, because OPG was associated with VC, but not with vascular disease.