Laufsport und Diabetes mellitus: Akuteffekte aerober Laufbandbelastungen auf die Glukosehomöostase und weitere metabolische Parameter bei Typ-1-Diabetikern sowie Langzeiteffekte einer sechsmonatigen strukturierten Trainingsintervention auf die pharmakologische und nicht-medikamentöse Therapie bei Typ-1-und Typ-2-Diabetikern

Background Regular physical activity is generally considered to be health-promoting in type-1-and type-2-diabetics (DDG 2008, BÄK/KBV/AWMF 2013, Esefeld et al. 2015, Esefeld and Halle 2015, Predel 2015). As far as type-2-diabetes mellitus (T2DM) is concerned, physical activity is a core interventional strategy, whereas diabetes management in type-1-diabetes mellitus (T1DM) mainly aims at avoiding hypo-and hyperglycemia (DDG 2008, Esefeld et al. 2015). The main reasons for higher inactivity in diabetics compared to the general population (Plotnikoff et al. 2006, Krug et al. 2013, Bohn et al. 2015) are fear of hypoglycemia (Brazeau et al. 2008) among type- 1-diabetics and insufficient motivation or compliance with exercise training among type-2-diabetics (Colberg et al. 2010, BÄK/KBV/AWMF 2013, Rise et al. 2013, Esefeld et al. 2015, Esefeld and Halle 2015, Tsasis et al. 2016). A basic prerequisite for safe and sustainable participation of diabetics in physical activities is the promotion of profound individual health competences by educational work (Rise et al. 2013, Rudinger 2015, Predel 2015). Guideline recommendation on diabetes management is primarily based on cycle ergometry. Different muscular demands of various sports activities are disregarded as well as age-specific investigations in type-1-diabetics above the age of 40. (Kraus and Latsch 2015). Running as a common recreational sports activity has rarely been investigated in diabetic patients. Therefore sports-specific investigations linked to everyday routine are desirable to promote safe and healthy behavior, especially in middle-aged diabetics (Cotter et al. 2014, Kraus and Latsch 2015). Objective Acute and long-term effects of running are investigated in patients with diabetes mellitus Type 1 and 2. In part one different levels of continuous aerobic running exercise in middle-aged type-1-diabetics are compared with regard to acute effects on glucose homeostasis, heart rate, acid-base and fluid balance in order to gain insights for enhanced diabetes management strategies. In part two a six-monthly supervised running program is analyzed for long-term effects on antidiabetic pharmacotherapy, HbA1c, weight and individual feeling of fitness to examine the importance of this approach in connection with diabetes therapy. Method Part 1: Nine male type-1-diabetics (Ø 53,4y.) familiar with running were examined in the scope of an accompanying measure of their training. In a two-day-interval they completed a continuous treadmill running of 60 minutes at 75% of their individual 4,0mmol lactate threshold (75%V4) and of 30 minutes at 90% their individual 4,0mmol lactate threshold (90%V4). The following metabolic parameters were collected at baseline and across an interval of 15 minutes during each running episode: Glucose concentration (Glc), lactate value (Lac), heart rate (HF), pH level (pH), arterial carbon dioxide partial pressure (pCO2), bicarbonate level (HCO3 -), base excess (BE), potassium (K+) and sodium concentration (Na+). Part 2: 237 diabetics with varying running experience (107 type-1-diabetics, Φ45,9y., 130 type-2-diabetics, Φ56,3y.) from the Diabetes Programm Deutschland (DPD) 2011-2013 were assessed retrospectively. The six-monthly running program consisted of a biweekly supervised running session of 60 to 90 minutes each accompanied by informational events on various health-related topics. 75% of the six-monthly workout consisted of low to moderate and 25% of vigorous continuous running sessions. Participants had different levels of running experience and baseline glycemic control (HbA1c) was mainly in line with guideline recommendation (≤7,5%). 80,8% of the type-2-diabetics were under antidiabetic treatment, 26,2% received insulin therapy. Individual training loads were adjusted by heart rate control and by a running instructor´s subjective assessment. The following parameters were collected at baseline and after six months by means of a questionnaire: HbA1c (%), antidiabetic pharmacotherapy, HbA1c linked to pharmacotherapy, weight (kg) and individual feeling of fitness (German school grades scale 1-5). Results Part 1: Eight of nine running episodes at 90%V4 and seven of nine running episodes at 75%V4 were included in the overall evaluation. The remaining three running episodes were analyzed separately due to indications of ketotic metabolic stress. At 90%V4 (n=8) initial glucose concentration declined by 28,22% and 47,14% (minute 15 and 30 respectively). At 75%V4 (n=7) it was reduced by 10,59%, 23,77%, 31,67% and 37,20% (minute 15, 30, 45 and 60 respectively). Differences between 90%V4 and 75%V4 were statistically significant at minute 15 (p=0,002) and minute 30 (p=0,001). Steady-state lactate values were significantly higher at 90%V4 compared to 75%V4 (p=0,015 and p=0,011 for minutes 15 and 30 respectively), with all lactate values being below the 4,0mmol threshold. Steady-state heart rate was also significantly higher at 90%V4 (p=0,001 for minutes 15 and 30 respectively). With regard to pH level, pCO2, HCO3 -, BE, Hct, K+- and Na+ greater effects were shown at 90%V4 versus 75%V4 without reaching statistical significance. Part 2: After six month of training type-1- and type-2-diabetics showed significant improvements in HbA1c (T1DM: -0,17±0,50%, p=0,001; T2DM: -0,36±0,91%, p=0,001), weight (T1DM: -1,44±3,12kg, p<0,001; T2DM: -1,7±3,4kg, p<0,001) and individual feeling of fitness (T1DM: school grades scale improvement of 0,5±1,0, p<0,001; T2DM: 0,9±1,1, p<0,001). For both types of diabetes 91% of HbA1c reductions were achieved without increases of antidiabetic pharmacotherapy. For groups with low, medium or high level of running experience HbA1c values were similar at baseline and after six months respectively (p>0,05). Reductions in antidiabetic pharmacotherapy were seen in about one third of both types of diabetes. 11,0% of the type-2-diabetics were able to take off an antidiabetic drug during the intervention. Proportion of type-2-diabetics without any antidiabetic pharmacotherapy rose from 19,2% at baseline to 23,1% after six months. Summary and Conclusion The structured and supervised six-monthly running program within the DPD showed significant improvements in HbA1c, weight and individual feeling of fitness for both types of diabetes. Moreover, antidiabetic pharmacotherapy was stabilized or reduced in the majority of cases. Diabetic patients with good metabolic control or comprehensive running experience at baseline were able to benefit from the running program as well suggesting that it can generally be regarded as a meaningful supplement to antidiabetic pharmacotherapy. The insights from the acute effects of different levels of continuous aerobic running exercise on glucose homeostasis, heart rate, acid-base and fluid balance may give prospects for further improvements of a running program: Adjustments of training loads in diabetics by individual lactate thresholds seem appropriate to ensure running in the aerobic zone. Furthermore, this method is suitable for daily use. Despite longer exercise duration, running with 75%V4 compared to 90%V4 appears to be less critical for treatment adjustments, since it is linked to less disturbances of various metabolic parameters, particularly with regard to glucose concentration, lactate value and heart rate. Guideline recommendation based on cycle ergometry might only be applicable to low-intensity aerobic running exercise (75%V4). As far as higher aerobic intensity is concerned, however, glucose consumption seems to be higher in running (90%V4). Inadequate individual health competence (Predel 2015) is still an issue in daily running sessions of experienced diabetics as shown by three running episodes with indications of ketotic metabolic stress. This underscores the need for sports-specific investigations linked to everyday routine particularly with regard to larger participant groups to promote safe and healthy behavior in diabetics (Cotter et al. 2014, Kraus und Latsch 2015).