Longitudinal associations between BMI change and the risks of colorectal cancer incidence, cancer-relate and all-cause mortality among 81,388 older adults

Abstract

BackgroundIt remains controversial whether weight change could influence the risks of colorectal cancer (CRC) and mortality. This study aimed to quantify the associations between full-spectrum changes in body mass index (BMI) and the risks of colorectal cancer (CRC) incidence, cancer-related and all-cause mortality among midlife to elder population.MethodsA total of 81,388 participants who were free of cancer and aged 55 to 74 years from the Prostate, Lung, Colorectal, and Ovarian (PLCO) screening program were involved. The percentage change of BMI was calculated as (BMI in 2006 - BMI at baseline)/BMI at baseline, and was categorized into nine groups: decrease (≥ 15.0%, 10.0–14.9%, 5.0–9.9%, 2.5–4.9%), stable (decrease/increase < 2.5%), increase (2.5–4.9%, 5.0–9.9%, 10.0–14.9%, ≥ 15.0%). The associations between percentage change in BMI from study enrolment to follow-up (median: 9.1 years) and the risks of CRC and mortality were evaluated using Cox proportional hazard regression models.ResultsAfter 2006, there were 241 new CRC cases, 648 cancer-related deaths, and 2361 all-cause deaths identified. Overall, the associations between BMI change and CRC incidence and cancer-related mortality, respectively, were not statistically significant. Compared with participants whose BMI were stable, individuals who had a decrease in BMI were at increased risk of all-cause mortality, and the HRs were 1.21 (95% CI: 1.03–1.42), 1.65 (95% CI: 1.44–1.89), 1.84 (95% CI: 1.56–2.17), and 2.84 (95% CI: 2.42–3.35) for 2.5–4.9%, 5.0–9.9%, 10.0–14.9%, and ≥ 15.0% decrease in BMI, respectively. An L-shaped association between BMI change and all-cause mortality was observed. Every 5% decrease in BMI was associated with a 27% increase in the risk of all-cause mortality (HR = 1.27, 95% CI: 1.22–1.31, p < 0.001). The results from subgroups showed similar trends.ConclusionsA decrease in BMI more than 5% shows a significantly increased risk of all-cause mortality among older individuals; but no significant association between increase in BMI and all-cause mortality. These findings emphasize the importance of body weight management in older population, and more studies are warranted to evaluate the cause-and-effect relationship between changes in BMI and cancer incidence/mortality.

Body mass index trajectories during mid to late life and risks of mortality and cardiovascular outcomes: Results from four prospective cohorts

“…complete-case regression analyses), with preexisting illness at baseline (including history of CHD, CHF, stroke, COPD or cancer), or with the highest weight variability; 2) we repeated the main analysis separately in each cohort; 3) we used the change in BMI relative to baseline BMI as the exposure variable (percent change of BMI) to evaluate the corresponding risks. Percent change of BMI was calculated as (last time BMI –baseline BMI)/baseline BMI [47] . Furthermore, subgroup analyses were conducted to evaluate whether the relationship between different BMI trajectories and outcomes differed by age (<60 or >=60 years), sex, race (white or non-white), smoking status (never, current or former smokers) and baseline BMI (normal, overweight or with obesity).…”

The association of weight change and all-cause mortality in older adults: a systematic review and meta-analysis

“…Twenty-nine studies examined change in weight; 17 of 29 studies reported % change and six studies examined change in BMI. Nineteen studies were conducted in the USA [4,[18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35], nine in Europe [36][37][38][39][40][41][42][43][44], three in Australia [6,45,46] and four in Asia [47-50]. Follow-up duration ranged from two [20] to 20 years [39], and participants were aged between 65 and 99 years.…”

Impact of optional multidisciplinary tumor board meeting on the mortality of patients with gastrointestinal cancer: A retrospective observational study

“… 20 Other evidence supporting our finding comes from Li et al, who found that for each 5% decrease in BMI, there was a 27% increase in overall mortality; they concluded that increased mortality was linked to lower BMI. 21 In contrast, Shaukat et al's study on CRC mortality found that a higher BMI was related to increased mortality. 22 These findings may guide the MDT and improve a patient's general health by the inclusion of not only physicians but also nurses and nutritionists in the MDT.…”