AMD related to Kidney disease
AMD related to kidney disease? A new study finds a relationship between serum cystatin C level (a measure of kidney function) and chronic kidney disease (defined by glomerular filtration rate) with the incidence of AMD.

The finding of a relationship of complement factor H Y402H (1277T->C) genotype status to both age-related macular degeneration (AMD) and kidney disease has led to speculation that kidney disease might be associated with AMD. Furthermore, many factors associated with chronic kidney disease such as oxidative stress, inflammation, and endothelial dysfunction have been hypothesized to have a role in the pathogenesis of AMD.

Cystatin C is abundant in retinal pigment epithelium (RPE) cells and has been hypothesized to have a role in the pathogenesis of AMD. Cystatin C is an inhibitor of cysteine proteinases (known as cathepsins). It has been hypothesized that cathepsins are involved in the pathogenesis of AMD. Data from cell culture and animal studies suggest that cathepsins may maintain homeostasis of the retinal photoreceptors and the extracellular environment of the Bruch membrane. The deleterious effect of a high serum cystatin C concentration is postulated to be due to its reduction of the protective effect of cathepsins. Inhibition of cathepsins increases the release of antineogenic endostatins from Bruch membrane, resulting in higher risk of exudative AMD. Serum levels of cystatin C tend to be higher in persons with impaired kidney function.

This research analyzed data from the Beaver Dam Eye Study, a population-based study of 4926 residents of Beaver Dam, Wisconsin that were aged 43 to 86 years at baseline. AMD was determined by grading photographs of the macula. The level of serum cystatin C was determined using a nephelometer. Individuals were defined as having mild or moderate to severe chronic kidney disease based on a glomerular filtration rate of more than 45 mL/min/1.73 m2 to 60 mL/min/1.73 m2 or less and 45 mL/min/1.73 m2 or less, respectively, according to the Modification of Diet in Renal Disease Study equation.
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While controlling for age and other risk factors, the level of serum cystatin C at baseline was associated with the 15-year cumulative incidence of early AMD (odds ratio: 1.16) and exudative AMD (1.42) but not geographic atrophy (0.89) or progression of AMD (1.02). Mild chronic kidney disease (defined by glomerular filtration rate) was associated with the 15-year cumulative incidence of early AMD (odds ratio: 1.36) but not the incidence of other AMD end points.

The researchers found that when controlling for age, sex, smoking status, and other risk factors, a higher level of serum cystatin C was associated with increased risk of incident early AMD and exudative AMD. The effect was stronger for incident exudative AMD in individuals without chronic kidney disease compared with those with chronic kidney disease, which suggests that this relationship might not be due to kidney-related processes. They also found a statistically significant relationship of mild chronic kidney disease (defined by glomerular filtration rate) with the incidence of early AMD but not with exudative AMD, geographic atrophy, or progression of AMD. The underlying biological processes responsible for these findings remain to be determined.

The investigators conclude that there is a relationship between the level of serum cystatin C and chronic kidney disease with the incidence of AMD.

Intake of citrus fruits—prevents Kidney stones. Really
Kidney stones strike more than a million Americans every year. Sometimes, it causes hurting to bring them factually to their knees.
Along with medication to dampen the formation of kidney stones, fatalities are often buoyant to make nutritional changes, among them intake of more citrus juices. Citrate in the fruit juices often reduces the creation of calcium oxalate stones and also lowers urine acidity, almost like the kidney stone prescription potassium citrate.