Association of neovascular age-related macular degeneration and hyperhomocysteinemia.

PURPOSE: To assess the relationship between plasma homocysteine levels and exudative neovascular age-related macular degeneration (AMD). DESIGN: Cross-sectional study. METHODS: A prospective comparative cross-sectional study was conducted in outpatient ophthalmology clinics in a university-affiliated medical institution. The cohort consisted of 59 patients (25 male, 34 female) with a mean age of 78 years (standard deviation [SD] = 8.4) with neovascular AMD who were candidates for photodynamic treatment. Patients were compared for plasma homocysteine levels with 58 patients who had dry AMD (24 male, 34 female) with a mean age of 76.3 years (SD = 8.4) and with a control group of 56 age-matched subjects (27 male, 29 female), with a mean age of 77.3 years (SD = 8.2). A 3-ml venous blood sample was obtained from each participant after an 8-hour fast. Levels of plasma homocysteine were measured by high performance liquid chromatography. The main outcome measure was hyperhomocysteinemia, defined as a plasma homocysteine level above 15 micromol/l. RESULTS: Homocysteine levels were higher by 27.9% in the neovascular AMD than in the dry AMD group, and by 21.9% than in the control group (P <.02). Hyperhomocysteinemia was found in 44.1% of the study group, in 22.4% of the dry AMD group, and in 21.4% of the control group (P =.011). CONCLUSIONS: This study suggests an association between an elevated plasma level of homocysteine and exudative neovascular AMD but not dry AMD.

Elevated homocysteine levels in young male patients with schizophrenia.

OBJECTIVE: Elevated plasma homocysteine has been found to be a risk factor for Alzheimer's disease as well as cerebral vascular disease, suggesting that some risk factors can accelerate or increase the severity of several CNS disease processes. The authors measured plasma homocysteine levels in patients with chronic schizophrenia in their catchment area. METHOD: A one-way analysis of covariance with age and sex as covariates was performed on the total plasma homocysteine levels of 193 patients with schizophrenia compared with 762 subjects without the diagnosis of schizophrenia who were evaluated in a screening program for employee health. RESULTS: The effect of schizophrenia was marked: the mean homocysteine level was 16.3 micro M (SD=11.8) in patients with schizophrenia compared with 10.6 micro M (SD=3.6) in healthy comparison subjects. The difference between groups was almost entirely attributable to the homocysteine levels of young male patients with schizophrenia. CONCLUSIONS: Elevated levels of homocysteine in young male patients with schizophrenia could be related to the pathophysiology of aspects of this illness.

Hyperhomocysteinemia in children on renal replacement therapy.

Hyperhomocysteinemia is an independent risk factor for the development of atherosclerosis in adult patients on dialysis or after kidney transplantation. There are few data on homocysteine (Hcy) concentrations in children under these circumstances. The aim of our study was to evaluate plasma Hcy levels and their determining factors in children on renal replacement therapy. In 29 children and adolescents on chronic dialysis therapy and in 34 children after renal transplantation (Tx) fasting total plasma Hcy, red blood cell (RBC) folate, and serum vitamin B(12) levels were measured. The plasma Hcy levels were expressed as number of standard deviations (SD) from mean level in age- and gender-matched controls. In dialysis patients the mean plasma Hcy level was elevated (4.4+/-0.8 SDs), without significant difference between patients on hemodialysis or continuous cycling peritoneal dialysis. In the dialysis patients a negative correlation ( r=-0.49) between plasma Hcy levels and RBC folate concentrations was found. Oral folate supplementation was given to 8 of 21 dialysis patients, resulting in high RBC folate levels (>800 micro g/ml) and normalization of the plasma Hcy levels (0.4+/-0.5 SDs). In Tx patients the mean plasma Hcy level was 5.6+/-1.4 SDs. Multivariate regression analysis revealed that the main factor determining Hcy level after kidney Tx was creatinine clearance. Patients with normal kidney function had a mean Hcy concentration of 1.69+/-0.86 compared with 10.0+/-2.2 in children with decreased function. Folate and cyclosporine levels had less significant effects on Hcy concentrations. Seven patients who were evaluated while on dialysis and after a successful kidney Tx demonstrated a significant reduction in Hcy levels. Children and adolescents on dialysis therapy and with impaired renal function after renal Tx have significant hyperhomocysteinemia. Oral folate supplementation normalizes the increased plasma Hcy levels and should be added to the medical treatment of all children with impaired renal function.

Homocysteine blood level in long-term care residents with oropharyngeal dysphagia: comparison of hand-oral and tube-enteral-fed patients.

BACKGROUND: Levels of homocysteine, methylmalonic acid, and relevant vitamins were measured and evaluated in patients with oral dysphagia (OD) receiving long-term care (LTC). METHODS: Group A was composed of 26 orally fed patients, and group B was composed of 25 patients who were fed by nasogastric tube. All patients were hospitalized in the LTC departments of the Geriatric Medical Center, Shmuel Harofe. General and nutritional status were assessed, and levels of vitamins including B12, folate, and B6 were measured along with serum homocysteine and urine methylmalonic acid levels. RESULTS: Homocysteine levels were significantly higher in the orally fed patients (p < .001); 92% had higher-than-normal homocysteine levels. The levels of vitamins B12, folate, and B6 were significantly lower in the orally fed patients (p < .001), although in most patients levels were in the normal range. Notably, the levels of homocysteine were significantly correlated with the levels of all vitamins but not with the albumin or hemoglobin values. Levels of methylmalonic acid were also higher in the orally fed patients, but the difference was not statistically significant, and there was no correlation between vitamin level and methylmalonic acid level. CONCLUSIONS: Orally fed patients with OD have substantially higher homocysteine levels and appreciably lower levels of the relevant vitamins than patients with OD who receive tube feeding. Therefore, homocysteine measurement may be the preferred indicator of vitamin intake in orally fed patients with OD.