High MBL-expressing genotypes are associated with deterioration in renal function in type 2 diabetes

Area of Science:

• Immunology
• Endocrinology
• Nephrology

Background:

• Mannan-binding lectin (MBL) is a potential prognostic biomarker for diabetic complications.
• MBL serum levels are primarily determined by MBL genotype.
• Type 1 diabetes (T1D) shows higher MBL levels for a given genotype, but this is unconfirmed for Type 2 diabetes (T2D).

Purpose of the Study:

• To investigate the impact of MBL genotypes on renal function and MBL serum levels in T2D patients.
• To compare MBL genotypes and serum levels between newly diagnosed T2D patients and healthy controls.
• To explore associations between MBL genotypes, insulin resistance, and body composition.

Main Methods:

• Cross-sectional study of 100 T2D patients and 100 matched healthy individuals.
• Measurements included serum MBL levels, MBL genotype, biochemistry, and DEXA scans.
• A 5-year follow-up assessed clinical status and micro/macroalbuminuria, with 12-year data for renal function.

Main Results:

• Similar serum MBL levels and genotype distributions were observed between T2D patients and controls.
• No significant difference in MBL levels for a given genotype was found between groups at baseline or 5-year follow-up.
• Plasma creatinine increased more rapidly in T2D patients with high MBL expression genotypes over 12 years (p=0.029).
• Serum MBL inversely correlated with body fat percentage in high MBL expression genotypes.
• Serum MBL did not correlate with diabetes duration or HbA1c.

Conclusions:

• Unlike T1D, T2D is not inherently associated with altered MBL serum levels for a given genotype.
• High MBL expression genotypes in T2D patients are associated with renal function deterioration.
• Serum MBL shows an inverse correlation with body fat percentage, particularly in individuals with high MBL expression genotypes.