Association between diabetic peripheral neuropathy and lower limb muscle strength in patients with type 2 diabetes mellitus: A systematic review and meta-analysis.

Purpose: Lower limb muscle strength is often reduced in patients with type 2 diabetes and is associated with a lower quality of life and poorer walking ability. Diabetic peripheral neuropathy (DPN) may contribute to muscle weakness, though evidence is inconsistent. No meta-analysis has specifically examined the effect of DPN on lower limb muscle strength. This study aimed to review the literature and assess whether lower limb muscle strength is reduced in individuals with DPN compared to those without DPN.

Methods: MEDLINE, Embase, and CENTRAL were searched for cohort and case-control studies on the association between DPN and lower limb muscle strength in individuals with type 2 diabetes. We pooled mean differences and standard deviations using random effects models. We evaluated the risk of bias in the included studies using the Quality in Prognosis Studies tool and determined the certainty of the evidence using the Grading of Recommendations Assessmet, Development and Evaluation (GRADE) approach.

Results: Overall, 25 studies for qualitative synthesis and 23 (2,798 participants) for meta-analysis were selected. The methodological quality demonstrated a moderate risk of bias in 72% of the included studies. There was low-certainty evidence of an association between DPN and lower extremity muscle strength (standardized mean difference -0.46, 95% CI -0.65 to -0.27).

Conclusions: Patients with type 2 diabetes and DPN may have lower muscle strength than those without DPN. Moreover, they should be informed of the risk of muscle weakness. Further research is needed to identify factors contributing to lower extremity weakness in DPN and determine which muscle groups are most susceptible.