Clinical treatment of patients with substance use disorder: The role of physical health

Abstract

It has been well documented that substance use disorder (SUD) patients suffer a high prevalence of cardiovascular disease, other lifestyle related diseases and have a decreased life expectancy of 15-20 years. However, their physical health status has been unclear. Furthermore, it has been uncertain if physical training, as a part of clinical treatment, could be a feasible and good strategy to counteract the patient groups’ physical as well as mental challenges. The objectives of this thesis were: 1. To evaluate key components for aerobic endurance and skeletal muscle strength in SUD patients. 2. To assess skeletal properties along with skeletal muscle strength and neuromuscular function in the lower extremities of amphetamine users. 3. Examine the effect and feasibility of high aerobic intensity interval training in SUD patients in clinical treatment. 4. Examine the effect and feasibility of maximal strength training in SUD patients in clinical treatment. In paper I we observed that SUD patients on average had a reduced aerobic capacity (VO2max) (15% for men and 25% for women), walking efficiency (12% for men and 15% for women) and maximal strength (30% for men and 33% for women) compared to healthy individuals. Such reductions are associated with an elevated risk of cardiovascular disease, cancer, mental health and premature death. In paper II we observed that amphetamine users also suffer reduced bone mineral density (BMD) (on average 8% for men and 7% for women) at several skeletal regions compared to healthy individuals. The impairments were accompanied by reduced maximal muscle strength and rate of force development (RFD). In paper III we documented the effect and feasibility of a high aerobic intensity training intervention in clinical treatment. Following the 8 weeks training intervention the SUD patients improved their aerobic capacity by 15 ± 7%, likely resulting in a substantial risk reduction for developing cardiovascular disease and other life style related diseases. Similarly as the aerobic endurance intervention, we documented the effect and feasibility of a strength training intervention in clinical treatment in paper IV. The eight week maximal strength training (MST) resulted in large improvements in maximal muscle strength (88 ± 54%) and RFD (82 ± 29%), likely predominantly due to adaptions in the nervous system. The improvements in muscular strength and function are associated with decreased risk of falls and fractures, osteopenia and osteoporosis and improved motor function and quality of life. Additionally, both paper III and IV confirmed the attenuation of aerobic endurance and muscular strength in SUD patients, before the training was carried out. In general, the physical measurements were not associated with the type of primary drug the SUD patients were using. This indicates that the systematic physical health reductions SUD patients suffer may be a consequence of an inactive lifestyle rather than direct damage by the actual drug use. In conclusion, this thesis advocates the importance of effective physical training as a part of clinical treatment of SUD patients.