To our knowledge this is the first randomized-controlled trial showing a benefit of exergaming for a clinical endpoint and for the quality of life of a disease. In this study we demonstrate a significant reduction of HbA1c, weight and BMI during the 12-week intervention. The majority of participants reported having played together with family members, and that the extent of their physical activity increased not only during exergaming but also in everyday life. Significant improvements in diabetes-dependent impairment, subjective wellbeing and quality of life as well as a reduction of depression were observed. Therefore, exercise games may potentially be used in a home setting as a tool to reduce sedentary behavior in T2DM.
It has been known for a long time that lifestyle intervention programs are successful for the treatment of patients with manifested T2DM. The Look-AHEAD (Action For Health in Diabetes) study [1, 9] demonstrated that with a combination of a calorie restricted diet, exercise, motivation and self-monitoring of blood glucose, patients could achieve a decrease of mean HbA1c from 7.3 to 6.6%, an 8.6% weight loss, and a significant reduction of anti-diabetic medication within one year. After four years, HbA1c reduction was maintained at -0.36% and weight loss at -6.2% . Also a recent meta-analysis of community-based physical activity for adults with type 2 diabetes revealed a significant lowering of HbA1c levels by -0.32% [95% CI -0.65, 0.01] . However, it needs to be emphasized that such interventions required an enormous amount of personal and economical effort. In contrast, in our approach, mentoring and costs were low, just mailing the Wii console with balance board, and the exercise game Wii Fit Plus. For the point of view of the participants, the use of the game was a low-threshold proposal for lifestyle intervention. In detail, we did not test the effect of physical activity on glucometabolic control, but just the effect of providing a device for interactive exercise in order to encourage self-motivation in the participants. Nevertheless, a comparable HbA1c reduction of 0.3% was reached and the percentage of participants reaching the HbA1c goal of <7.0%  increased by 9%. A meta-analysis investigating the efficacy of pharmacological therapies demonstrated that the amount of HbA1c reduction essentially depends on baseline HbA1c . HbA1c reduction seems to be greater the higher the baseline levels had been previously. With a mean baseline HbA1c of 7.0-7.9%, therapies with oral antidiabetic medication achieved an HbA1c reduction of 0.1%, while in our study the baseline HbA1c in the intervention group was 7.1 ± 1.3%, and a reduction of 0.3% was achieved.
Data about the use of exercise games for lifestyle intervention in the elderly are scarce, although a systematic review revealed significant health benefits in older adults . For Wii Fit, especially, it has already been shown that regular use might be a vehicle for increasing physical activity in the elderly . Moreover, cycling games seem to increase cognition in older adults . It has also been used for lifestyle intervention in adolescents to encourage them to lose weight . Overweight school children were encouraged to play an exercise game for 30-60 min/school day for a period of 20 weeks during lunch-time or after school. Adolescents played with or against a peer to expend calories, while in the control group participants played alone. Within this controlled setting, the highest weight loss with a mean of 1.7 ± 4.5 kg was achieved with cooperative playing, and also measurements for self-efficacy increased. This finding is fully in line with our results, demonstrating that the majority of participants preferred to play with family members rather than by themselves. Since key motivators to physical activity were weight management, feelings of physical and mental well being, as well as social relationships associated with physical activity, exercise games should help to motivate players to exercise, and could take advantage of group dynamics to motivate players in terms of the duration of the exercise period . Obviously, the motivating effects are not only short-term but are maintained and sufficient to significantly reduce long-term blood-glucose parameters such as HbA1c. Another study including adolescents playing exercise games alone or with a virtually present partner demonstrated significantly higher persistence in all experimental conditions with the virtual partner present . One explanation for this might be the finding that cooperative exercise gaming produces a higher intrinsic motivation that comes from a desire for control and this is related to a higher expenditure of energy . Therefore, exercise games are mostly played in a social context . This might not be true only for youngsters, but also for the elderly, since a meta-analysis reported significant mental health outcomes in the majority of the reviewed studies, resulting in positive consequences for physical and lastly social health in older adults .
Key motivations for playing exercise games were perceptions of enjoyment, feeling better afterwards and participation in a social context . This is fully in line with our results, which demonstrated that during the 12-week exercise game intervention, diabetes-dependent impairment decreased, and mental health, subjective wellbeing and quality of life improved significantly. The combination of physical activity per se, the feeling of having done something positive for one’s health, and playing fun games with family members seems to strengthen patients’ motivation, resulting not only in weight loss and improvement of glucometabolic control but also in an positive attitude towards life.
Our study has several limitations that need to be considered. First, a completer rate of only 67% was achieved and of those a completer analysis had been performed. The patients who managed to improve their glucometabolic control may have been more strongly motivated to stay with the program. This might have biased the results and the effects might have been weakened in the complete study population. Nevertheless, the percentage of drop out in our study are comparable to those seen in other exercise interventions for older adults  and the fact that the baseline characteristics of completers and dropouts, the results of the intention-to-treat analysis as well as the outcomes in both groups after exercise intervention did not differ, argues against such a responder bias. Second, it might be seen as limitation of our study that the exercise game was used at home in an uncontrolled setting and that no objective information was obtained about the duration and intensity of exercising. However, it was our particular aim to create a situation close to real-life, where T2DM patients were not enclosed in an expensive and all-embracing mentoring program but had the opportunity of performing physical activities on their own in order to demonstrate the potential of a low-threshold intervention for clinical outcomes. Therefore, we refrained from close supervision. Third, data was self-reported and clinical parameters were not measured in a standardized manner but at local laboratories. This did not affect the intra-individual analysis because glucometabolic measurements were performed at baseline and at end of study in the same local laboratory and were reported in written form by the attending physician. In assessing physical activity, diabetes-dependent impairment, subjective wellbeing and quality of life, validated self-assessment questionnaires were used and the comparison baseline vs. end of study was performed using the same algorithm. It might be speculated that the patients participating in this study might have been more strongly motivated than the general T2DM population. Nevertheless, that might be true for all patients participating in clinical studies. Perhaps those patients who had heard about the Wii and exercise games from their children or grandchildren might have been more willing to participate, but generally, for all T2DM patients who are physically able, exercise games might offer an alternative form of home exercise.