VLCD & adjuvant exercise effect (vascular & metabolic) in overweight
Research type
Research Study
Full title
Exploring the immediate and short-term effects of a very low calorie diet (VLCD) with and without adjuvant exercise training on lean body mass (LBM), vascular function, metabolic health and muscle protein synthesis (MPS) in overweight diabetic individuals.
IRAS ID
255016
Contact name
Iskandar Idris
Contact email
Sponsor organisation
University of Nottingham
Duration of Study in the UK
1 years, 11 months, 28 days
Research summary
Sarcopenia is defined as the incremental age-related loss of skeletal muscle in humans which generally begins from forty years old. It is associated with an overall reduction in quality of life and increased morbidity and mortality. Patients with type two diabetes mellitus (T2DM) are particularly at risk of developing sarcopenia, partly due to the condition and also due to the common incidence after or during middle age.
A promising recently-investigated and effective conservative approach to T2DM is through very low calorie diets (VLCD). Some studies have shown that the diabetic status of some patients can be reversed through VLCD. However, VLCD will theoretically result in an acceleration of sarcopenia. This presents as a limiting factor for the implementation of VLCD in this at-risk patient group.
Skeletal muscle tissue is encouraged to grow in size or be maintained through two means - an increase in circulating protein breakdown products, or through resistance exercise (RE). Additionally, RE has been shown to increase the body’s sensitivity to insulin, the main hormone which controls circulating glucose levels and is frequently impaired in T2DM, as well as temporarily decreasing glucose levels. The precise mechanism by which these happen is not fully understood yet.
In this study, the effect of one form of RE (high intensity interval training, HIT) is used, with or without protein supplementation, in a VLCD in overweight, middle-aged male patients with T2DM. We aim to recruit 12 patients into each group (interval training, resistance training, control) at our centre. Patient weight, markers of muscle protein synthesis, glucose levels and changes to blood vessels will be investigated before, during and after across a six week timeframe. Investigations will include muscle and fat biopsies, blood samples, ultrasound scans, strength testing, echocardiogram and deuterium oxide (D2O) isotope ingestion for later non-invasive body fluid sample mass spectrometric analysis.Summary of Results
There has been increased interest in the feasibility of very-low energy diets (VLEDs) as a potential treatment for obesity. However, concerns have been raised in relation to the potential of diet-induced muscle loss in population subgroups which exhibit a default susceptibility to primary sarcopenia. Exercise has frequently been explored as a potential attenuator of lean body mass (LBM) reductions in hypocaloric states through altered rates of muscle protein synthesis (MPS) and breakdown (MPB). The musculoskeletal, cardio-metabolic and vascular effects of VLEDs, with or without High Intensity Interval Training (HIIT) is investigated.Methods:
Human interventional trial with a randomised-controlled, supervised, open-label design, consisting of two arms (800kcal/day VLED-only versus an equivalent VLED intervention with HIIT), undertaken in a single-centre setting. Male patients with either insulin-independent type 2 diabetes mellitus (T2DM) or prediabetes, aged 30-to-65 years and a body mass index (BMI) of 27-to-50kg/m2 were recruited. An intervention duration of six weeks, with baseline, peri- and post-intervention assessments occurred.
Results:
Participants in the VLED-HIIT group lost more total and fat mass versus VLED-Only. However, estimation of MPS, revealed a greater reduction in VLED-HIIT than VLED-Only. LBM loss was also found to be greater in VLED-HIIT than VLED-Only. Paradoxically, although within-group MPB measures were non-significant, a larger proportion in the VLED-HIIT group exhibited a reduction post-intervention and an improvement in muscular strength. VLED-Only also preferentially improved glucose-related parameters.
Conclusion:
VLEDs were safely implemented and well-tolerated in both groups. The presented, novel evidence concerning LBM retention is conflicting and requires further investigation
REC name
East Midlands - Derby Research Ethics Committee
REC reference
19/EM/0227
Date of REC Opinion
10 Oct 2019
REC opinion
Further Information Favourable Opinion