Serum Indicators Of Lipid Metabolism In Diabetic Patients – Are They A Potential Risk Factor For Senile Nuclear Cataract?

The aim of this study was to quantify serum indicators of lipid metabolism in diabetic patients with nuclear cataract. Lipid metabolism indicators analyzed in this study were total serum cholesterol, triglycerides, HDL (high-density lipoprotein) cholesterol and LDL (low-density lipoprotein) cholesterol.  Inclusion criteria were age ≥ 45 years, diabetes and hyperlipidaemia. Exclusion criteria were age <45 years, other type of cataract (traumatic, uveitic, presenile) and inherited disorders of lipid metabolism. The research was conducted from January 2021. to January 2022.  at the University Eye Clinic, University Hospital Centre Osijek.

This case-control study included 150 patients divided in three groups. The first group was consisted of patients with diabetes and senile nuclear cataract, second group was consisted of patients with diabetes, hyperlipidemia and senile nuclear cataract and third group was control group (diabetics without cataract). All participants underwent complete ophthalmological examination and ophthalmological history data were collected.

The grade of opacity of the lens was determined during slit lamp examination according LOCS III (Lens Opacity Classification System III). The grading was conducted by two specialists of ophthalmology.  The participants from first two groups were the one already appointed for the cataract surgery, while the control group were diabetic patients regularly planned for ophthalmological examination. All measures of lipid serum levels were conducted at Department for Laboratory Diagnostics, University Hospital Centre Osijek on Clinical Chemistry Analyzer AU680 (Beckam Coulter, USA). The Beckman Coulter, USA assay was used to quantify lipid serum levels.

Kruskal–Wallis one-way analysis of variance (p=0,002717) confirmed statistically significant difference in total serum cholesterol distribution between the groups. The mean  value of total serum cholesterol  in the control group was 4,85 mmol/l (SD 1,37), in the first group 5,21 mmol/l (SD 1,05) and in the second group 4,43 mmol/l (SD 0,98). Kruskal–Wallis one-way analysis of variance (p= 0,0004359) confirmed statistically significant difference in LDL- cholesterol distribution between the groups. The mean  value of LDL-cholesterol  in the control group was 2,87 mmol/l (SD 0,87), in the first group   3,03 mmol/l (SD 0,74) and the second group 2,43 mmol/l (SD 0,70).

The value of total serum cholesterol was significantly higher in the first group of patients (p=0,002).  The value of LDL-cholesterol was significantly lower (p=0,00043)  in the second group of patients compared to a control group and the first group of patients. The plasma membrane of lens fiber cells contains a significantly high proportion of cholesterol molecules which is indispensable for lens epithelial cells development and in maintaining the transparency of the lens. The higher values of total serum cholesterol can be a risk factor for diabetic cataract development.