Differing Impact of Weight Cycling on Ambulatory Blood Pressure Versus Conventional Blood Pressure Assessment: A Possible Explanation to Controversy

Abstract

BACKGROUND: Weight Cycling (WC) is a widespread behavior associated with deleterious cardiovascular (CV) health, including elevated blood pressure (BP). Yet, a 2010 review analyzing the effects of WC on BP concluded there was not enough quality evidence to draw any sort of decisive conclusions. Ambulatory BP (ABP) monitoring is recognized as a superior method of measurement and predictor of the CV state when compared to traditional laboratory BP assessment. The impact that WC may have on ABP per se is unknown. METHODS: Impact of self-reported WC history on ABP was assessed via a causal comparative non-experimental design. Sixty-five women completed the Weight and Lifestyle Inventory questionnaire (WALI). The WALI has been shown to be a reliable index of WC (r=.87, P<0.001). Subjects were classified as weight cyclers (WC) if they reported a weight loss of ≥ 4.5 kg at least 3 times followed by weight regain. Those who reported less than this were classified as non-weight cyclers (NWC). Main outcome was mean differences between groups on laboratory BP and ABP. RESULTS: WC (n=31) were older (39.7±8.9 vs 33.1±11.3 yr), had a higher percent body fat (47.1±6.2 vs 41.4±7.8 (%)), and were less fit (21.2±5.4 vs 26.7±7.6 ml.kg-1.min-1) than NWC (n=34). No significant differences were found for laboratory BP values. WC women had higher systolic (130.1±13.6 vs 122.0±8.2 mmHg, P=0.006) and diastolic (76.2±8.9 vs 70.0±9.0 mmHg, P=0.011) ABP values than NWC women. Systolic (23% versus 17%, P <0.001) and diastolic (13% versus 9%, P < 0.001) BP load was higher for WC compared to NWC women. CONCLUSION: WC may deleteriously impact BP outcomes that might only be witnessed when ABP monitoring is used.