Effect of Combined Exercise Training on Physical and Cognitive Function in Women With Type 2 Diabetes

The impact of early-life exercise on CREB-signaling pathway and hippocampus neuroplasticity in diabetic adult male rats; the study of developmental model

BACKGROUND

Childhood exercise enhances brain structure, while diabetes detrimentally affects it. This study examines early-life exercise's influence on adult diabetic rats' memory and neuroplasticity.

METHODS

Male Wistar pups were divided into Control, Diabetes, Exercise Training, and Diabetes exercise groups. Diabetes was induced on day 23 with Alloxan (200 mg/kg). A 3-week regimen included aerobic and resistance training thrice weekly. The aerobic intensity was 70%, and resistance varied from 50% to 100% of the maximal carrying capacity (MCC). Following the last training sessions, spatial memory and retrieval tests were performed in infancy, childhood, and emerging adulthood using the Morris Water Maze test (MWM). The hippocampus was excised to measure protein and gene expression of brain-derived neurotrophic factor (BDNF), calmodulin-dependent protein kinase (CAMKII), N-methyl-D-aspartate receptors (NMDAR), and cAMP-response element-binding protein (CREB) by western blotting and reverse transcription-polymerase-chain reaction (RT-PCR) methods. Blood samples were collected during each developmental stage to measure glucose levels, at the study's conclusion, to assess Interleukin-1β levels using the ELISA method. The Nissel staining assessed dead hippocampal cells in CA1.

RESULTS

Post-natal exercise improved spatial memory (p < 0.05) and glucose levels (p < 0.05) in diabetic rats during adolescence and emerging adulthood. Despite reduced mRNA expression (NMDAR 40%, BDNF 62%, CREB 43%, CAMKII 66%), diabetic rats, by study end, showed increased BDNF, NMDARR, CAMKII, CREB protein/gene expression (p < 0.05) in emerging adulthood for both training groups.

CONCLUSION

Early-life exercise influenced hippocampal BDNF/NMDAR-CAMKII/CREB pathways in a diabetic rat model, highlighting post-natal exercise's role in neuroplasticity memory enhancement and improved glucose level.

Feasibility and preliminary efficacy of different intensities of functional training in elderly type 2 diabetes patients with cognitive impairment: a pilot randomised controlled trial

BACKGROUND

Aging and type-2 diabetes (T2D) are the most important risk factors for cognitive impairment and Alzheimer's disease. Exercise training is an effective, safe, and practical intervention in improving glucose metabolism, physical function, and cognitive disorders. This pilot study investigated the feasibility and preliminary efficacy of high-intensity low-volume (HIFT) vs. low-intensity high-volume (LIFT) functional training in elderly T2D patients with cognitive impairment.

METHODS

Forty-eight elderly T2D patients (31 female, 17 male, age 67.5 ± 5.8 years, MMSE score 18.8 ± 2.6, FBG 209.5 ± 37.9) were randomly assigned to HIFT, LIFT and control groups. Cognitive impairment was diagnosed with MMSE ≤ 23 based Iranian society. The SDMT, CVLT-II, BVMT-R, and Stroop tests were used to evaluated processing speed, learning, memory and attention respectively. Physical fitness tests include: tandem stance and walk test; TUG; 6MWT, 10MWT; SSST; 5TSTS; and hand grip was used to evaluated static and dynamic balance, agility, walking endurance, gait speed, lower limb function and lower and upper body strength respectively. As well as, Biochemical (FBG, insulin, HOMA-IR, HbA1c) and physiological outcomes (SBP, and DBP) were assessed. The HIFT group performed six weeks of functional training (three sessions per week) with 120-125% of the lactate threshold. The LIFT group performed six weeks of functional training (five sessions per week) with a 70-75% lactate threshold. Feasibility, safety, and acceptability of exercise programs were assessed at the end of the study.

RESULT

HIFT showed a higher adherence rate (91% vs. 87.5%), safety, and acceptability compared to LIFT. MMSE and Stroop scores, 6MWT, FBG, insulin, HOMA-IR, HbA1c, SBP, and DBP significantly improved in HIFT (all, P ≤ 0.004) and LIFT (all, P ≤ 0.023). Changes in 6MWT, FBG, insulin, HOMA-IR, and HbA1c in HIFT (all, P ≤ 0.001) and LIFT (all, P ≤ 0.008) were significant compared to the control group. Changes in Stroop scores were significant only in the HIFT group compared to the control group (P = 0.013). SDMT, CVLT-II, BVMT-R, balance test, 10MWT, SSST, TUG and hang grip significantly improved only in HIFT (all, P ≤ 0.038).

CONCLUSION

HIFT vs. LIFT is a safe, feasible, and effective approach for improving some aspects of physical, biochemical, and cognitive function in elderly T2D patients with cognitive impairment. This pilot study provides initial proof-of-concept data for the design and implementation of an appropriately powered randomised controlled trial (RCT) of HIFT vs. LIFT in a larger sample of elderly T2D patients with cognitive impairment.

TRIAL REGISTRATION

Randomized controlled trial (RCT) (Iranian Registry of Clinical Trials, trial registration number: IRCT20230502058055N1. Date of registration: 11/06/2023.

Effectiveness of Combined Aerobic and Resistance Exercise on Cognition, Metabolic Health, Physical Function, and Health-related Quality of Life in Middle-aged and Older Adults With Type 2 Diabetes Mellitus: A Systematic Review and Meta-analysis

OBJECTIVES

To evaluate the effectiveness of combined aerobic and resistance exercise on cognition, metabolic health, physical function, and health-related quality of life (HRQoL) in middle-aged and older adults with type 2 diabetes mellitus (T2DM).

DATA SOURCE AND STUDY SELECTION

Systematic search of CINAHL, Cochrane, EMBASE, Scopus, PubMed, ProQuest Dissertation and Thesis, PsycINFO, Web of Science databases, and gray literature from Google Scholar. Pertinent randomized controlled trials (RCTs) were selected. The Protocol was registered in the International Prospective Register of Systematic Reviews (PROSPERO CRD42023387336).

DATA EXTRACTION

The risk of bias was evaluated using the Cochrane Risk of Bias tool by 2 reviewers independently. Outcome data were extracted in a fixed-effect model if heterogeneity test were not significant and I2≤50%; otherwise, the random-effects model was used.

DATA SYNTHESIS

Sixteen studies with 2426 participants were included in this review. Combined aerobic and resistance exercise had significant positive effects on cognition (SMD=0.34, 95% CI: 0.13 to 0.55), metabolic health on HbA1c (SMD=-0.35, 95% CI: -0.48 to -0.22) and lipid profile (total cholesterol SMD=-0.20, 95% CI: -0.34 to -0.07; low-density lipoprotein SMD=-0.19, 95% CI: -0.33 to -0.05; high-density lipoprotein SMD=0.25, 95% CI: 0.12 to 0.39; and triglycerides SMD=-0.18, 95% CI: -0.31 to -0.04), physical function on aerobic oxygen uptake (SMD=0.58, 95% CI: 0.21 to 0.95) and body mass index (MD=-1.33, 95% CI: -1.84 to -0.82), and physical HRQoL (MD=4.17, 95% CI: 0.86 to 7.48). Our results showed that clinically important effects on cognition may occur in combining the low-moderate intensity of aerobic exercise and progressive intensity of resistance training, the total duration of the exercise needs to be at least 135 minutes per week, among which, resistance training should be at least 60 minutes.

CONCLUSION

Combined aerobic and resistance exercise effectively improves cognition, ameliorates metabolic health, enhances physical function, and increases physical HRQoL in middle-aged and older adults with T2DM. More RCTs and longitudinal follow-ups are required to provide future evidence of structured combined aerobic and resistance exercise on other domains of cognition.