People with obesity and type 2 diabetes tend to have lower levels of certain muscle-derived signaling molecules—irisin, BDNF, and cathepsin B—that are linked to muscle health and brain function, and this reduction may help explain why these individuals often experience both muscle loss and memory problems.
Evidence from Studies
No evidence studies found yet.
What Would Prove This
Per GRADE and EBM methodology, here is what ideal scientific evidence would look like to definitively prove or disprove this claim, ordered from strongest to weakest.
A meta-analysis of standardized circulating myokine levels across diverse, well-characterized cohorts of obese and diabetic individuals versus healthy controls, controlling for age, sex, BMI, and physical activity, to determine if reductions in irisin, BDNF, and CTSB are reproducible and quantifiable.
A systematic review and meta-analysis of at least 20 high-quality, peer-reviewed studies measuring serum or plasma irisin, BDNF, and CTSB in adults aged 40–75 with obesity (BMI ≥30) or type 2 diabetes (HbA1c ≥6.5%) compared to age- and sex-matched healthy controls, using standardized ELISA or mass spectrometry methods, with pooled effect sizes and heterogeneity analysis.
Whether interventions that increase irisin, BDNF, or CTSB levels in obese or diabetic individuals lead to measurable improvements in muscle mass or cognitive performance, establishing a direct link between myokine modulation and functional outcomes.
A double-blind, placebo-controlled RCT of 150 adults with obesity and prediabetes (HbA1c 5.7–6.4%) randomized to 12 weeks of supervised aerobic exercise (150 min/week at 70–80% HRmax) plus daily vitamin D (2000 IU) versus placebo, measuring pre- and post-intervention serum irisin, BDNF, CTSB, lean mass via DXA, and cognitive function via MoCA and Trail Making Test.
Whether persistently low levels of irisin, BDNF, and CTSB predict the future development of sarcopenia or cognitive decline in a population with metabolic disease over time.
A prospective cohort study following 500 adults aged 50–70 with obesity and/or type 2 diabetes for 5 years, measuring baseline and annual serum levels of irisin, BDNF, and CTSB alongside annual assessments of muscle strength (grip strength, SPPB), lean mass (DXA), and cognitive performance (MMSE, digit symbol substitution), adjusting for physical activity, diet, and comorbidities.
The strength and direction of the association between circulating myokine levels and concurrent measures of muscle function or cognition in a defined population with metabolic disease.
A cross-sectional analysis of 300 adults with type 2 diabetes, measuring serum irisin, BDNF, and CTSB alongside grip strength, 6-minute walk distance, and Montreal Cognitive Assessment scores, with adjustment for age, sex, HbA1c, BMI, and medication use.
Whether isolated cases of extreme myokine deficiency correlate with severe sarcopenia or cognitive impairment in metabolic disease, suggesting rare but clinically relevant phenotypes.
A case series of 10 individuals with type 2 diabetes and HbA1c >9% who exhibit both severe sarcopenia (SARC-F score ≥11) and moderate cognitive impairment (MoCA <20), with detailed measurement of serum irisin, BDNF, and CTSB levels and exclusion of other neurological or muscular disorders.