ASSOCIATION OF EXERCISE WITH DEVELOPING METABOLIC SYNDROME IN PROSTATE CANCER PATIENTS ON ANDROGEN DEPRIVATION THERAPY: A SECONDARY ANALYSIS OF A RANDOMIZED CONTROLLED TRIAL

Purpose:

To determine if prostate cancer (PCa) patients on androgen deprivation therapy (ADT) have lower odds of developing metabolic syndrome (MS) if they were meeting exercise guidelines.

Materials and Methods:

This is an exploratory analysis of a Phase III multicentre double blind, randomized controlled trial where normoglycemic men with prostate cancer planned for at least 9 months ADT were randomized 2:1 to receive metformin 850 mg or placebo BID orally for 18 months (NCT03031821; The PRIME study). At baseline, all study participants were provided a copy of the Canadian Physical Activity Guideline. At baseline and 12 months, participants completed the modified Godin Leisure Time Exercise Questionnaire which was used to calculate whether they were meeting the aerobic and strength exercise guidelines. The associations between meeting the exercise guidelines and the development of MS at 12 months was analyzed as the primary outcome using logistic regression. The associations between meeting the exercise guidelines and body weight (BW), waist circumference (WC), and hemoglobin A1C (HbA1c) were analyzed as secondary outcomes.

Results:

At baseline, 87/90 (96.6%) and 45/45 (100%) patients in the metformin and placebo arms completed the exercise questionnaires. At baseline, aerobic exercise guidelines were met by 26/87 (29.9%) and 12/45 (26.7%) patients in the metformin and placebo arms, respectively. Strength exercise guidelines at baseline were met by 40/87 (46%) and 14/45 (31.1%) in the metformin and placebo arms. At 12 months, aerobic exercise guidelines were met by 31/84 (36.9%) and 17/42 (40.5%) patients in the metformin and placebo arms, respectively. Strength exercise guidelines at 12 months were met by 22/84 (26.2%) and 13/42 (30.9%) in the metformin and placebo arms. The association of exercise (either strength or aerobic) with the outcome (MS) was not modified by the intervention (metformin versus placebo), or vice versa, on testing for interactions. Proportion of patients with MS in the metformin and placebo arms were 37/87 (42.5%) versus 26/45 (57.8%) at baseline and 44/83 (51.0%) versus 25/44 (56.8%) at 12 months, respectively. The likelihood of developing MS at 12 months was significantly reduced in the patients meeting aerobic exercise guidelines [odds ratio 0.38 (95% CI: 0.18 - 0.79); p=0.01], but not in those who met the strength exercise guidelines. Significant reductions in BW [-7.13 (95% CI -13.46 – -0.79); p<0.03] and WC [-6.88 (95% CI -11.61 – -2.15); p<0.001] were associated with meeting the strength exercise guidelines. Significant reductions in WC [-6.37 (95% CI -1.72 – -2.02); p<0.001] and HbA1c [-0.16 (95% CI -0.29 – -0.02); p=0.02] were associated with meeting the aerobic exercise guidelines.

Conclusions:

This exploratory analysis shows favourable differences in MS, BW, WC, and HbA1c at 12 months in PCa patients on ADT who meet exercise guidelines. These efficacy signals warrant confirmation as a primary analysis in future.