Circulating Midkine as a Biomarker of Diabetic Kidney Disease in Patients with Type 2 Diabetes Mellitus
Hassan Haider KhudhirAbstract:
BACKGROUND:
Diabetic nephropathy (DN) is a primary driver of end-stage renal disease (ESRD) worldwide. Traditional markers, such as serum creatinine and microalbuminuria, lack the sensitivity required to detect early subclinical renal decline, often signaling irreversible macrovascular damage. There is an urgent clinical need for a novel, noninvasive circulating biomarker capable of staging early-onset metabolic and structural renal injuries. This study evaluated the clinical utility of a novel biomarker comprising serum midkine (MK) levels to map the progressive transition from a healthy metabolic state through uncomplicated type 2 diabetes mellitus (T2DM) to advanced DN.
METHODS:
In this cross-sectional, comparative study, 120 age-matched participants were stratified into three groups: healthy controls (
RESULTS:
Serum MK levels progressively increased across the groups, peaking in the DN group (940 pg/mL) at nearly double the concentration of the DM (525 pg/mL) and control (450 pg/mL) groups. Females maintained higher baseline MK values across all groups, though DN males exhibited the highest absolute range (up to 2357 pg/mL).
CONCLUSIONS:
Serum MK serves as a clear biomarker for progressing kidney damage in T2DM, showing a distinct escalation from early metabolic stress to severe DN. This upward trend is independent of patient age, and while baseline variations exist between genders, the overall surge remains tightly linked to structural renal decline. Consequently, monitoring MK levels offers strong clinical utility for the early detection and tracking of DN alongside traditional filtration metrics.