Homocysteine and Diabetic Retinopathy

Abstract

OBJECTIVE -Homocysteine is an emerging risk factor for cardiovascular and nondiabetic ocular vaso-occlusive diseases. However, studies of the relationship between homocysteine and diabetic retinopathy have reported inconsistent results. The purpose of this study was to evaluate the relationship between plasma total homocysteine concentration and diabetic retinopathy. RESEARCH DESIGN AND METHODS -We assessed the homocysteine-retinopathy relationship in 168 men and women with type 2 diabetes in a community-based, cross-sectional study. We photodocumented diabetic retinopathy status and measured plasma total homocysteine concentration using a commercial fluorescence polarization immunoassay enzymatic kit. Data for selected clinical/demographic variables and established risk factors for diabetic retinopathy were obtained from fasting blood samples and an interviewer-assisted lifestyle questionnaire.RESULTS -A higher mean plasma total homocysteine concentration was observed in diabetic individuals with retinopathy than in those without retinopathy (11.5 mol/l [95% CI 10.4 -12.5] vs. 9.6 mol/l [9.1-10.2], P ϭ 0.001). Furthermore, the relationship between homocysteine and diabetic retinopathy was not explained by renal dysfunction and was independent of the other major risk factors for diabetic retinopathy (duration of diabetes, A1C, and systolic blood pressure) and determinants of higher homocysteine concentrations (age, sex, and red cell folate) (odds ratio 1.20 [95% CI 1.023-1.41], P ϭ 0.024).CONCLUSIONS -Plasma total homocysteine concentration may be a useful biomarker and/or a novel risk factor for increased risk of diabetic retinopathy in people with type 2 diabetes. Diabetes Care 31:50-56, 2008H omocysteine has generated considerable interest in recent years as both a sensitive biomarker of folate deficiency and an emerging risk factor for cardiovascular disease (even within the normal range of homocysteine concentrations) (1) and has been linked to vasoocclusive diseases in the eye (2). The known determinants of higher fasting plasma homocysteine levels are older age, male sex, and certain genetic abnormalities, while the major risk factors for hyperhomocysteinemia (elevated plasma total homocysteine concentration) are impaired renal function and poor vitamin B status (particularly folate status but also vitamin B6 and B12 status). In the elderly (age Ͼ75 years), hyperhomocysteinemia is generally associated with low folate status or renal impairment (3).In addition, a multitude of physiological, lifestyle, and drug associations with higher homocysteine concentrations have been reported, including positive associations with smoking and alcohol and coffee intake (4). Numerous studies have evaluated the diabetic retinopathyhomocysteine relationship (Table 1) but have yielded inconsistent results (5-28), possibly as a result of methodological differences and residual confounding. We hypothesized that homocysteine is associated with diabetic retinopathy in type 2 diabetes, independent of the major determinants of bo...

Relationship between metformin use, vitamin B12 deficiency, hyperhomocysteinemia and vascular complications in patients with type 2 diabetes

“…Rather unexpectedly, it was not significantly related to history of macroangiopathy in our patients. Our finding is compatible with the data presented by recent studies which inferred that elevated HC was a risk factor for retinopathy [11,22,23]. Nevertheless, it should be noted that plasma HC concentration was only marginally higher (P =0.05) in the metformin users than the non-metformin users and prevalence of retinopathy was not significantly different between the two groups.…”

Comparison of plasma homocysteine levels in patients with type 2 diabetes mellitus with normal subjects

“…6,7 Oküler hastalıklardan ise lens ektopisi, optik atrofi, retinal arter ve ven tıkanıklığı, yaşa bağlı maküla dejenerasyonu ve DR ile ilişkili olduğu bildirilmektedir. [8][9][10][11][12] Literatürde diabetik hastalarda plazma homosistein düzeylerinin değerlendirildiği çalışmalarda çelişkili sonuçlar bildirilmektedir, normal popülas-yondan yüksek, düşük veya benzer düzeyde göste-rildiği çalışmalar mevcuttur. [13][14][15] Çalışmamızın amacı, diabetik hastalarda plazma homosistein düzeyle-rini sağlıklı bireylerle karşılaştırmak ve retinopatinin şiddeti ile ilişkisini değerlendirmektir.…”

Homocysteine in the Pathogenesis of Chronic Glaucoma

“…Many studies since have confirmed this association for type 2 diabetes mellitus as well. [57][58][59] It is also true that severity of retinopathy correlates strongly with Hcy level, independent of glycaemic control. 60 Higher Hcy levels are observed in individuals with proliferative retinopathy compared to non-proliferative retinopathy, even though in both instances the levels are significantly elevated compared to control.…”