Identifying glucose thresholds for incident diabetes by physiological analysis: a mathematical solution.

Area of Science:

• Endocrinology
• Metabolic Diseases
• Clinical Diagnostics

Background:

• Current type 2 diabetes diagnosis relies on plasma glucose thresholds linked to retinopathy risk, an indirect and potentially imprecise method.
• Understanding glucose homeostasis mechanisms, specifically insulin sensitivity and beta-cell function, offers a more direct approach to defining healthy glucose levels.

Purpose of the Study:

• To develop and validate novel, physiologically-based plasma glucose thresholds for type 2 diabetes risk assessment.
• To identify gender- and age-specific glucose level optimizations that maximize insulin sensitivity and beta-cell function.

Main Methods:

• A constraint optimization algorithm was employed to determine minimal glucose levels associated with maximal insulin sensitivity and beta-cell function.
• Data from a training cohort (n=1,474) with clamp-measured insulin sensitivity and oral glucose tolerance test (OGTT)-derived beta-cell function were used.
• Optimized thresholds were validated in three independent prospective cohorts (n=5,593) assessing progression to diabetes.

Main Results:

• Optimized fasting glucose thresholds ranged from ≤87 mg/dl (women ≤45) to ≤95 mg/dl (men >45).
• Optimized 2-hour OGTT glucose thresholds ranged from ≤96 mg/dl (women ≤45) to ≤105 mg/dl (men >45).
• Individuals exceeding these optimized thresholds showed a significantly higher odds ratio (3.74) for diabetes progression compared to conventionally defined prediabetes (2.32).

Conclusions:

• Physiologically-based, gender- and age-specific glucose thresholds can be determined by optimizing insulin sensitivity and beta-cell function.
• These novel thresholds are more predictive of type 2 diabetes progression than current diagnostic criteria.
• This approach offers a more accurate and mechanistic basis for diagnosing diabetes and identifying at-risk individuals.