Effects of Aerobic Training on Pancreatic Fat and Cognitive Function in T2DM Patients

The primary aim of this study was to evaluate the difference in cognitive function and brain functional structure between exercise group and control group by performing regular one-year moderate-intensity aerobic training in type 2 diabetes mellitus (T2DM) with normal cognitive function. The secondary aim of this study was to explore the effects of six-month regular moderate-intensity aerobic training on pancreatic fat content, metabolic index of glucose and lipid, as well as cardiovascular risks in patients type 2 diabetes mellitus.

In recent years, more attention has been paid to the role of aerobic exercise in improving cognitive ability, but there is still a lack of prospective studies on the T2DM population with normal cognitive function. Therefore, the purpose of this study is to compare the differences of cognitive function and hippocampal volume between exercise group and non-exercise group by regular moderate-intensity aerobic exercise intervention for one year in T2DM patients with normal cognitive function to evaluate the impact of aerobic exercise on cognitive function and hippocampal volume for these patients and provide scientific evidence for early prevention and delaying the occurrence of cognitive dysfunction in patients with T2DM. Pancreatic fat deposition in patients with type 2 diabetes is not only a simple fat accumulation but also an early marker of insulin resistance. In this study, The effectiveness of six months of an aerobic exercise intervention on pancreas fat reduction for type 2 diabetes patients was examed.

In this study, 106 T2DM patients who met the inclusion criteria were enrolled and randomized into two groups. All patients received diabetes education(once a month, the course will be focused on basic knowledge of diabetes, diet management, and blood glucose monitoring). The control group followed their regular lifestyle without exercise intervention and recorded 24-hour dietary intake. The aerobic training group was supervised by the trainers who had received professional training and given 60min moderate aerobic rhythmic exercise (including 5min warm-up, 50min aerobic exercise, and 5min stretching exercise).

Baseline assessment included demographic data, duration of diabetes, body mass index（BMI）, waist circumference（WC）, hip circumference（HC）, systolic blood press（SBP）, diastolic blood press（DBP）, smoking and drinking, drug use, acute and chronic complications of diabetes, other chronic complications, 24-hour diet review, international physical activity questionnaire (IPAQ).

Evaluation after 6 months of intervention included pancreatic fat content(PFC), liver fat content (LFC), visceral adipose tissue (VAT), subcutaneous adipose tissue(SAT), fasting plasma glucose (FPG), 2-hour postprandial blood glucose(2hPG), hemoglobin A1c(HbA1c), fasting insulin (FINS), homeostasis model assessment of insulin resistance(HOMA2-IR), homeostasis model assessment of Beta-cell function (HOMA2-β), early insulin secretion index(Δ I30 / Δ G30), total cholesterol(TC), triglycerides(TG),high-density-lipoprotein-cholesterol(HDL-C),low-density lipoprotein cholesterol(LDL-C). The Framingham cardiovascular risk scale (Framingham) and 10-year ischemic cardiovascular disease risk assessment (ICVD) scores were calculated.

Evaluation after 12 months of intervention included fasting plasma glucose(FPG),30 minutes postprandial glucose(30minPG), 2-hour postprandial glucose(2hPG)，hemoglobin A1c(HbA1c), fasting insulin(FINS),30 minutes Insulin(30minINS), homeostasis model assessment of insulin resistance(HOMA2-IR),homeostasis model assessment of Beta cell function(HOMA2-β),early insulin secretion index(Δ I30 / Δ G30),totalcholesterol(TC),triglycerides(TG),high-density-lipoprotein cholesterol( HDL-c），low-density-lipoprotein cholesterol(LDL-c),muscle mass, right, left hippocampal volume of hippocampal volume, the hippocampal volume, and total physical activity energy expenditure, total moderate physical activity energy expenditure. In addition to this, cognitive function (MMSE, MoCA) were also evaluated.

Eligibility Criteria:
Inclusion Criteria:

1. Diagnosed of T2DM based on the 1999 diagnostic criteria of the WHO;
2. Had normal muscle strength; 3.18.5≤BMI≤35kg/m2;

4.Had normal cognitive function ( MMSE ≥27 points, MoCA ≥26 points) ; 5.Primary school education or above ( Participants were able to fill in the scale) ; 6.Aged 60-75 years; 7.Had ≥5 years duration of T2DM; 8.Had no evidence of hearing or visual impairment and communication difficulties; 9.Were willing to participate in the study and signed informed consent voluntarily.

Exclusion Criteria:

1. With severe acute complications of diabetes;
2. Serious heart, liver and kidney dysfunction, and cardiovascular and cerebrovascular diseases, such as cerebral infarction, cerebral hemorrhage, etc.;
3. Pregnant and lactating women;
4. Sleep disorders (PSQI \>7 points);
5. Had a family history of dementia;
6. Alcohol dependence and oral medications that affect cognitive function (such as antipsychotic drugs, sedative hypnotics, etc.);
7. Contraindications for MRI, such as metal implant in the body.