Relationship between Cardiometabolic Factors and the Response of Blood Pressure to a One-Year Primary Care Lifestyle Intervention in Metabolic Syndrome Patients

Abstract

Systemic hypertension has been recognized as a modifiable traditional cardiovascular risk factor and influenced by many factors such as eating habits, physical activity, diabetes, and obesity. The objective of this cross-sectional study was to identify factors that predict changes in blood pressure induced by a one-year lifestyle intervention in primary care settings involving a collaboration between family physicians, dietitians, and exercise specialists. Patients with metabolic syndrome diagnosis were recruited by family physicians participating in primary care lifestyle intervention among several family care clinics across Canada. Participants for whom all cardiometabolic data at the beginning (T0) and the end (T12) of the one-year intervention were available were included in the present analysis (n = 101). Patients visited the dietitian and the exercise specialist weekly for the first three months and monthly for the last nine months. Diet quality, exercise capacity, anthropometric indicators, and cardiometabolic variables were evaluated at T0 and at T12. The intervention induced a statistically significant decrease in waist circumference (WC), systolic (SBP) and diastolic (DBP) blood pressure, and plasma triglycerides, and an increase in cardiorespiratory fitness (estimated VO2max). Body weight (p < 0.001), body mass index (BMI) (p < 0.001), and fasting blood glucose (p = 0.006) reduction, and VO2max increase (p = 0.048) were all related to changes in SBP. WC was the only variable for which changes were significantly correlated with those in both SBP (p < 0.0001) and DBP (p = 0.0004). Variations in DBP were not associated with changes in other cardiometabolic variables to a statistically significant extent. Twelve participants were identified as adverse responders (AR) in both SBP and DBP and displayed less favorable changes in WC. The beneficial effects of the primary care lifestyle intervention on blood pressure were significantly associated with cardiometabolic variables, especially WC. These findings suggest that a structured lifestyle intervention in primary care can help improve cardiometabolic risk factors in patients with metabolic syndrome and that WC should be systematically measured to better stratify the patient’s hypertension risk.

Keywords: adverse responders; blood pressure; cardiorespiratory fitness; lifestyle intervention; metabolic syndrome; primary care; waist circumference.

Figure 1

Flowchart of the patient’s eligibility in the present study. Abbreviations: CHANGE, Canadian Health Advanced by Nutrition and Graded Exercise; T12, end of intervention at 12 months.

Figure 2

The CHANGE program protocol.

Figure 3

Association between changes in SBP and WC (Figure 2A) and DBP (Figure 2B) and changes in WC over a one-year lifestyle intervention. Groups 1 to 5 represent the distribution of participants according to the difference in WC between T0 and T12. 1, loss between 15.1 and 20 cm (n = 2); 2, loss between 15 and 10.1 cm (n = 9); 3, loss between 10 and 5.1 cm (n = 20); 4, loss between 5 and 0.1 cm (n = 46); and 5, gain between 0 and 4.9 cm (n = 18).

Figure 4

Association between changes in SBP (Figure 3A) and DBP (Figure 3B) and changes in VO₂max over a one-year lifestyle intervention. Groups 1 to 4 represent the distribution of participants according to the difference in VO₂max between T0 and T12. 1, loss between 0.1 and 3 mLO₂/kg/min (n = 8); 2, gain between 0 and 2.9 mLO₂/kg/min (n = 50); 3, gain between 3 and 5.9 mLO₂/kg/min (n = 29); and 4, gain between 6 and 8.9 mLO₂/kg/min.

Figure 4

Association between changes in SBP (Figure 3A) and DBP (Figure 3B) and changes in VO₂max over a one-year lifestyle intervention. Groups 1 to 4 represent the distribution of participants according to the difference in VO₂max between T0 and T12. 1, loss between 0.1 and 3 mLO₂/kg/min (n = 8); 2, gain between 0 and 2.9 mLO₂/kg/min (n = 50); 3, gain between 3 and 5.9 mLO₂/kg/min (n = 29); and 4, gain between 6 and 8.9 mLO₂/kg/min.