Despite the importance of physical activity (PA) for cardiovascular health, only 60% of the European population comply with the World Health Organization's recommendations (at least 150minutes of moderate PA per week).1 Effective interventions to encourage PA are urgently needed. The different strategies reported so far have shown a moderate effect for up to 3 to 6 months after the intervention, but there is little evidence from longer follow-up periods.2 In a clinical trial, our working group on primary cardiovascular prevention previously demonstrated the short-term positive impact on moderate PA of a 2-month training program (TP) delivered in primary care.3 The aim of the present study was to evaluate whether this effect persisted at 1 year after completion of the program.
The study design and methods have been described previously.3 Briefly, the program included sedentary patients of both sexes, aged between 35 and 70 years, who were at risk of cardiovascular events: with type 2 diabetes, metabolic syndrome, or hypertension, and at least 1 other cardiovascular risk factor. The control group (CG) and the intervention group (IG) received an educational talk on heart-healthy habits. The IG participated in an 8-week TP with 3 sessions per week of aerobic exercise and strength training, in groups of 6 supervised by a physiotherapist. The IG received a median [interquartile range] of 22 [20-23] exercise sessions per patient, with 91% [83%-95%] adherence. At the start of the program and at 1 year, PA was assessed with the international physical activity questionnaire (IPAQ) and the brief physical activity assessment tool, and physical condition was assessed with cardiopulmonary exercise testing on a treadmill (modified Bruce protocol) and a 6-minute walk test. The study was approved by the hospital ethics committee, with reference number EO/1220. Written informed consent was obtained from all participants.
Statistical analysis (between-group differences in changes in the variables analyzed) was performed with linear regression analysis, and regression coefficients and their 95% confidence intervals (95% CI) were determined with adjustment for the baseline values of the different outcome variables and for age and sex. Stata S/E v.13 software was used.
Of the 147 patients assessed and randomized at the start of the study (75 in the IG and 72 in the CG), 111 were included in the 1-year analysis (56 in the IG and 55 in the CG). No significant between-group differences were observed in the baseline characteristics for the group evaluated at 1 year (table 1). Cardiopulmonary exercise testing was maximal (maximum respiratory quotient> 1.1) in 62% of the patients at the baseline assessment and in 76.3% at the final assessment, with no differences between groups.
Baseline values for sociodemographic data, cardiovascular risk factors, and physical exercise for the patients assessed at 1-year of follow-up and between-group differences
| Control group (n=55) | Intervention group (n=56) | P | |
|---|---|---|---|
| Demographics | |||
| Age, y | 59.1±7.9 | 59.8±7.4 | .638 |
| Male | 29 (52.7) | 34 (60.7) | .396 |
| Abdominal circumference, cm | |||
| Men | 105.7±10.8 | 110.8±11.5 | .084 |
| Women | 110.0±8.2 | 105.8±13.4 | .189 |
| Body mass index | 31.1±4.1 | 30.8±4.7 | .702 |
| Smokers | 19 (34.5) | 20 (35.7) | .855 |
| Educational level | .606 | ||
| Primary education | 29 (52.7) | 30 (54.5) | |
| Secondary education | 20 (36.4) | 15 (27.3) | |
| Further education | 6 (10.9) | 10 (18.2) | |
| Live alone | 10 (18.2) | 4 (7.3) | .151 |
| Cardiovascular risk factors | |||
| Hypertension | 44 (80.0) | 50 (89.3) | .174 |
| Systolic blood pressure, mmHg | 139.7±15.7 | 143.9±17.1 | .177 |
| Diastolic blood pressure, mmHg | 89.8±9.1 | 90.4±8.9 | .753 |
| Dyslipidemia | 42 (76.4) | 44 (78.6) | .781 |
| Total cholesterol, mg/dL | 208.1±36.7 | 196.4±41.4 | .124 |
| HDL-C, mg/dL | 51.0±11.0 | 51.4±12.2 | .871 |
| LDL-C, mg/dL | 123.6±30.0 | 115.9±30.6 | .227 |
| Triglycerides, mg/dL | 148.7±101.1 | 149.2±81.6 | .979 |
| Diabetes | 30 (54.5) | 26 (46.4) | .392 |
| Glycated hemoglobin, % | 6.8±1.1 | 6.7±1.3 | .804 |
| Physical exercise | |||
| Sufficient amount of exercise*(≥ 360 MET-min/week) | 3 (5.4) | 2 (3.6) | .679 |
HDL-C, high-density lipoprotein cholesterol; LDL-C, low-density lipoprotein cholesterol; MET, metabolic equivalent.
Values are expressed as mean±standard deviation or No. (%).
The values at baseline and at 1 year for PA and physical condition, as well as between-group differences, are shown in table 2. At 1 year, the IG had a significantly greater increase than the CG for the overall IPAQ result (P=.001), due to a significantly greater increase in moderate PA (P=.002). The proportion of patients who at 1 year were doing a “sufficient frequency of physical exercise” (≥ 3 times/wk) was also significantly higher in the IG (41.1% vs 23.6%; P=.05). For physical condition, the IG group had significantly greater increases at 1 year than the CG in cardiopulmonary exercise test duration (P=.018) and in anaerobic threshold delay (P=.007). The results were similar in both age groups (younger and older than 60 years) and sex groups (male and female). Although the improvement in PA was generally somewhat higher in the men and the under 60s, the confidence intervals of the coefficients showed a clear overlap between subgroups (data not shown).
Baseline and final values (at 1-year of follow-up) for physical activity and physical condition and differences between the control and intervention groups
| Control group (n=55) | Intervention group (n=56) | β (95% CI)* | P | |||
|---|---|---|---|---|---|---|
| Baseline | Final | Baseline | Final | |||
| Physical activity | ||||||
| Total moderate activity,a MET-min/wk | 80 [0-360] | 80 [0-540] | 30 [0-210] | 390 [0-1200] | 398 (145; 651) | .002 |
| Total IPAQ,a MET-min/wk | 445 [198-891] | 876 [400-1551] | 427 [160-829] | 1473 [702-2085] | 504 (200; 809) | .001 |
| Walking activity,a MET-min/wk | 247 [0-742] | 495 [264-1140] | 198 [16-627] | 594 [198-1386] | 130 (–132; 392) | .326 |
| Time spent sitting,a min/wk | 2945 [1860-3600] | 2610 [2100-3390] | 2875[2055-3700] | 2575 [2040-3400] | 44.4 (–279;368) | .786 |
| Physical condition | ||||||
| 6-min walk test, m | 532±65.0 | 542±84.4 | 501±77.2 | 541±96.7 | 21.3 (–4.7; 47.4) | .107 |
| Peak VO2, mL/kg/min | 23.2±5.3 | 23.9±5.5 | 23.5±4.8 | 24.0±5.0 | –0.1 (–1.3; 1.2) | .932 |
| Exercise time, min | 11.0±3.4 | 12.4±3.1 | 11.3±3.0 | 13.2±2.4 | 0.7 (0.1; 1.3) | .018 |
| Peak oxygen pulse,b mL VO2/beat | 14.7±3.3 | 14.6±3.2 | 14.7±3.5 | 14.4±3.7 | –0.2 (–0.9; 0.5) | .546 |
| Maximum HR, beats/min | 138.5±18.8 | 138.7±17.1 | 139.6±17.6 | 143.2±16.8 | 3.8 (–1.3;8.9) | .144 |
| Maximum HR, % estimated maximum HRc | 85.6±10.6 | 86.2±10.4 | 86.9±10.4 | 89.5±10.3 | 2.6 (–0.6;5.8) | .115 |
| Time to AT, min | 9.8±2.5 | 9.9±2.7 | 9.8±2.6 | 10.7±2.4 | 0.9 (0.2; 1.5) | .007 |
| VO2 at AT, mL/kg/min | 21.1±4.4 | 20.4±3.7 | 21.5±4.4 | 20.0±4.8 | –0.2 (–1.4; 0.9) | .664 |
| CO2 equivalentd at AT | 27.1±3.4 | 26.9±2.6 | 26.8±3.0 | 27.8±3.4 | 0.5 (–0.2; 1.2) | .154 |
95% CI, 95% confidence interval; AT, anaerobic threshold; HR, heart rate; MET, metabolic equivalent; VO2, oxygen consumption.
Values are expressed as median [interquartile range] or mean±standard deviation.
This study demonstrates that the positive effect of the TP on PA persisted at 1 year after its completion, with the notable feature that, unlike other studies,4 there were no refresher sessions during the follow-up period. In another study that did not involve refresher sessions, the improvements at 1-year follow-up were mostly increased walking time, with no changes in moderate PA.5 With our TP, the increase in moderate PA of 360 MET-min/wk (90min/wk) was enough to improve certain physical condition variables, but not enough to significantly affect others, such as the 6-minute walk test and peak oxygen consumption (VO2). Although the 390 MET-min/wk (99 min/wk) of moderate PA recorded in the IG at 1 year after the TP did not meet the recommendatons,1 small increases in moderate PA are known to be associated with improvements in cardiovascular risk.4,6
The main limitation of this study is the self-reporting of PA using a questionnaire, which is known to overestimate accelerometer recordings.
In conclusion, this TP delivered in a primary care center had a positive impact on PA at 1 year. Key to encouraging medium-to-long-term improvements in PA with an effect on cardiovascular health are strategies involving health care professionals, delivered in primary care centers, with individualized assessment and close supervision.
FUNDINGStudy funded by a grant from the Fundació Docència i Recerca Mútua de Terrassa (XI Convocatoria de Becas de Investigación FMT, N.o BE080).
AUTHORS’ CONTRIBUTIONSDesign and field work: F. García-Ortún, Á. Jaén, L. Solá, L. González-Gil, A. Alvarez Auñon. Statistical analysis and writing first draft: F. García-Ortún, Á. Jaén, A. de la Sierra. All authors: review, writing, editing, reading, and approval of the final version.
CONFLICTS OF INTERESTThe authors declare no conflict of interests.
Juan Luis Molina Muñoz, for his collaboration in monitoring the training programs. Mari Carmen Creus Torra, for her collaboration on the educational component. Lola Mesa Sanchez, Marta Martinez Caballero, and Pilar Arcusa Solà, for their collaboration on the administrative field work.