Link between retinopathy and nephropathy caused by complications of diabetes mellitus type 2

Abstract

While the correlation and chronology of appearance of diabetic nephropathy and retinopathy is well known in diabetes mellitus (DM) type 1 patients, in DM type 2 this correlation is less clear. A retrospective study including 917 patients with type 2 diabetes. Diabetic retinopathy (DR) was diagnosed based on fundus photographs taken with a non-mydriatic camera. Diabetic nephropathy (DN) was diagnosed based on urinary albumin concentration in a morning urine sample. Statistical analysis was performed with a seemingly unrelated regression (SUR) model. Our SUR model is statistically significant: the test for "model versus saturated" is 2.20 and its significance level is 0.8205. The model revealed that creatinine and glomerular filtration rate (GFR) have strong influence on albuminuria, while body mass index (BMI) and HbA1c have less significant impact. DR is affected positively by diabetes duration, insulin treatment, glucose levels, and HbA1c, and it is affected negatively by GFR, triglyceride levels, and BMI. The association between DR and DN was statistically significant and had a unidirectional correlation, which can be explained by chronological order; that is, DN precedes DR. The present study indicates that the level of renal impairment is proportional to the level of damage to the eye. Furthermore, such an association has a chronological aspect; the renal injury precedes retinal damage.

Association between diabetic eye disease and other complications of diabetes: Implications for care. A systematic review

“…Interestingly, data from the Diabetes Control and Complications Trial (DCCT) in T1DM demonstrated that progression of DR independently increases the risk of development of nephropathy, and also showed that the development of nephropathy increases the risk of DR progression . Although a previous study demonstrated that these two complications influence the incidence of each other, a retrospective study in T2DM demonstrated that the association between DR and diabetic nephropathy is unidirectional and that renal injury precedes retinal damage . Accordingly, several studies have shown that nephropathy is a risk factor for DR, including severe forms of retinopathy .…”

“…29,30,37 In this regard, Kotlarsky et al concluded that renal injury precedes retinal damage, but they stated that prospective studies are required to confirm this conclusion. 37 Additionally, the reviewed evidence indicates that DR correlates with declining GFR 34,48 and, specifically, that retinopathy severity at baseline is a predictor of the rate of decline of eGFR. 48 An important implication of the above findings is that close monitoring of individuals with DR for the presence of other microvascular complications, particularly albuminuria and impaired glomerular function, may help prevent progression to more serious kidney disease.…”

“…27 Although a previous study demonstrated that these two complications influence the incidence of each other, 36 a retrospective study in T2DM demonstrated that the association between DR and diabetic nephropathy is unidirectional and that renal injury precedes retinal damage. 37 Accordingly, several studies have shown that nephropathy is a risk factor for DR, including severe forms of retinopathy. 28,[30][31][32] Concerning T1DM, a 20-year prospective study by Romero-Aroca et al found that both micro-and macroalbuminuria correlated with the development of VTDR but not with the development of any DR. 28 In the same study, DR was a significant risk factor for nephropathy.…”

Characteristics of diabetic nephropathy patients without diabetic retinopathy

“…[13] However, there were still many conditions that DN was not associated with DR, and the incidence of fundus lesions was inconsistent in different studies. [14–18] Characteristics of DN patients without DR are not fully clear yet.…”

Update on Diagnosis and Treatment of Diabetic Retinopathy: A Consensus Guideline of the Working Group of Ocular Health (Spanish Society of Diabetes and Spanish Vitreous and Retina Society)

“…The percentages of DR may vary from 85% for insulin-dependent patients to 58% for non-insulin-dependent patients for more than 15 years after diagnosis [20]. Dyslipidemia [21], puberty [22], pregnancy [23], diabetic nephropathy [24, 25], and obesity [26] have also been reported as risk factors for DR.…”