In this cross-sectional study of 1018 patients with T2DM, we investigated the association between Hcy and the prevalence of CKD. We found that the prevalence of CKD in T2DM patients increased with increasing Hcy, independent of age, race, sex, and other clinical variables. To our knowledge, this is the first study with a large patient population to demonstrate the association between Hcy and CKD in US patients with T2DM. Previously, diabetes, hypertension, hyperuricaemia, obesity, and hyperlipidaemia were identified as risk factors for CKD.Except for Hcy, our study showed that male sex, age, UA, TG, and HbA1c were associated with CKD. However, the associations among HbA1c, TG, and CKD were not significant.
In the last 10 years, Hcy has been regarded as a marker of cardiovascular disease and a definite risk factor for many other diseases. HHcy is a trigger for many diseases, such as atherosclerosis, congestive heart failure, age-related macular degeneration, Alzheimer’s disease and hearing loss.13 Several previous reports have assessed the association between Hcy and CKD. Li reported that Hcy is associated with tubular interstitial lesions in the early stages of IgA nephropathy.14 Wang found that HHcy was more prevalent in patients with IgA nephropathy than in patients with other primary glomerular diseases, especially in the early stages of CKD, and may be a predictor of accelerated decline in renal function and future incidence of CKD.15 Spence has shown that Hcy plays a significant role in the effect of renal dysfunction on atherosclerosis.16
Diabetes mellitus is the most common cause of CKD. The hemodynamic changes and abnormal glucose metabolism caused by hyperglycemia are the basis of renal damage.However, The exact mechanisms underlying the association between HHcy and renal disease progression are not fully understood. Possible reasons are that HHcy inhibits vasodilation of renal arteries, promoting acceleration of progression of renal damage, and promotes sclerotic process in glomeruli.17–19 Increasing evidence indicates that the potential causes of Hcy excretion are reduced in CKD patients.20Fig. 2 indicates that renal function gradually deteriorated with increasing Hcy levels. An Israeli study found that subjects with homocysteine > 15 µmol/L were more likely to have an eGFR < 60 ml/min and proteinuria. At a GFR < 60 ml/min, homocysteine was progressively elevated in stages 3 and 4 of CKD.9,21 This is consistent with our findings.It was found that the greater the duration of T2DM, the higher the levels of Hcy in the plasma.
This study had several limitations. First, this was a retrospective cross-sectional study that did not confirm the causal relationship between Hcy and CKD in patients with T2DM. Second, the covariates in this study did not include medications that might affect the results of Hcy detection.
Nevertheless, the strength of this study is the relatively large sample size in patients with T2DM. This study provides useful and convincing epidemiological evidence for the association between Hcy and CKD in patients with T2DM. In conclusion, Hcy was found to be independently associated with CKD in patients with T2DM. In the future, a prospective cohort study needs to be conducted to further investigate the impact of Hcy on CKD in patients with T2DM.