Revascularization in atherosclerotic renovascular disease: Problems beyond the obstruction

Inverse association between body mass index and chronic kidney disease in older diabetic adults

PURPOSE

To identify associations among body mass index (BMI), diabetes, and chronic kidney disease (CKD) in older adults in Taiwan.

METHODS

This study enrolled 3334 participants aged 65 years and above who underwent an annual health screening at a medical center from January 2006 to December 2010. CKD was defined as an estimated glomerular filtration rate less than 60 mL/min/1.73 m(2). A multiple logistic regression analysis was used to determine associations among BMI, diabetes, and CKD.

RESULTS

The prevalence rate of CKD was 19.7% and 10.5% in diabetic and nondiabetic subjects, respectively. A multivariate model indicated that age, diabetes, hypertriglyceridemia, low levels of high-density lipoprotein cholesterol, and hyperuricemia were associated with an increased risk of CKD. Furthermore, there was an inverse association between BMI and CKD in older diabetic patients, with odds ratios of 3.71, 2.32, 2.12, and 1.31 in underweight, normal, overweight, and obese subjects, respectively, compared with nondiabetic subjects of normal weight.

CONCLUSIONS

There was an inverse association between BMI and CKD in older diabetic patients but no such association was found in nondiabetic older adults. More attention should be given to older underweight diabetic patients because they have a higher risk of CKD.

Renovascular disease, microcirculation, and the progression of renal injury: role of angiogenesis

Emerging evidence supports the pivotal role of renal microvascular disease as a determinant of tubulo-interstitial and glomerular fibrosis in chronic kidney disease. An intact microcirculation is vital to restore blood flow to the injured tissues, which is a crucial step to achieve a successful repair response. The purpose of this review is to discuss the impact and mechanisms of the functional and structural changes of the renal microvascular network, as well as the role of these changes in the progression and irreversibility of renal injury. Damage of the renal microcirculation and deterioration of the angiogenic response may constitute early steps in the complex pathways involved in progressive renal injury. There is limited but provocative evidence that stimulation of vascular proliferation and repair may stabilize renal function and slow the progression of renal disease. The feasibility of novel potential therapeutic interventions for stabilizing the renal microvasculature is also discussed. Targeted interventions to enhance endogenous renoprotective mechanisms focused on the microcirculation, such as cell-based therapy or the use of angiogenic cytokines have shown promising results in some experimental and clinical settings.

Self-expanding nitinol renal artery stents: comparison of safety and efficacy of bare versus Polyzene-F nanocoated stents in a porcine model

OBJECTIVE

To investigate the safety and efficacy of a Polyzene-F nanocoat on new low-profile self-expandable nitinol stents in minipig renal arteries.

MATERIALS AND METHODS

Ten bare nitinol stents (BNS) and 10 stents coated with a 50 nm-thin Polyzene-F coating were randomly implanted into renal arteries of 10 minipigs (4- and 12-week follow-up, 5 animals/group). Thrombogenicity, on-stent surface endothelialization, vessel wall injury, late in-stent stenosis, and peristrut vessel wall inflammation were determined by quantitative angiography and postmortem histomorphometry.

RESULTS

In 6 of 10 BNS, >50% stenosis was found, but no stenosis was found in stents with a nanothin Polyzene-F coating. Histomorphometry showed a statistically significant (p < 0.05) different average maximum luminal loss of 55.16% ± 8.43% at 12 weeks in BNS versus 39.77% ± 7.41% in stents with a nanothin Polyzene-F coating. Stents with a nanothin Polyzene-F coating had a significantly (p < 0.05) lower inflammation score after 12 weeks, 1.31 ± 1.17 versus 2.17 ± 0.85 in BNS. The results for vessel wall injury (0.6 ± 0.58 for Polyzene-F-coated stents; 0.72 ± 0.98 for BNS) and re-endothelialization, (1.16 ± 0.43 and 1.23 ± 0.54, respectively) were not statistically significant at 12-week follow-up. No thrombus deposition was observed on the stents at either follow-up time point.

CONCLUSION

Nitinol stents with a nanothin Polyzene-F coating successfully decreased in-stent stenosis and vessel wall inflammation compared with BNS. Endothelialization and vessel wall injury were found to be equal. These studies warrant long-term pig studies (≥120 days) because 12 weeks may not be sufficient time for complete healing; thereafter, human studies may be warranted.

Age-related associations of hypertension and diabetes mellitus with chronic kidney disease

Background

Studies suggest end-stage renal disease incidence and all-cause mortality rates among patients with chronic kidney disease (CKD) differ by age. The association of diabetes mellitus and hypertension with CKD across the adult lifespan is not well established.

Methods

Data from NHANES 1999–2004 were used to determine the association of risk factors for stage 3 or 4 CKD (n = 12,518) and albuminuria (n = 12,778) by age grouping (20 to 49, 50 to 69, and ≥70 years). Stage 3 or 4 CKD was defined as an estimated glomerular filtration rate of 15 to 59 ml/min/1.73 m² and albuminuria as an albumin to creatinine ratio ≥30 mg/g.

Results

For adults 20 to 49, 50 to 69 and ≥70 years of age, the prevalence ratios (95% confidence interval) of stage 3 or 4 CKD associated with hypertension were 1.94 (0.86 – 4.35), 1.51 (1.09 – 2.07), 1.31 (1.15 – 1.49), respectively (p-trend = 0.038). The analogous prevalence ratios (95% confidence interval) were 3.01 (1.35 – 6.74), 1.61 (1.15 – 2.25), 1.40 (1.15 – 1.69), respectively, for diagnosed diabetes mellitus (p-trend = 0.067); and 2.67 (0.53 – 13.4), 1.35 (0.69 – 2.63), 1.08 (0.78 – 1.51), respectively, for undiagnosed diabetes mellitus (p-trend = 0.369). The prevalence ratios of albuminuria associated with hypertension and diagnosed and undiagnosed diabetes mellitus were lower at older age (each p < 0.05).

Conclusion

Among US adults, diabetes mellitus and hypertension are associated with CKD and albuminuria regardless of age. However, the associations were stronger at younger ages.