Weight gain ups cancer risk among middle-aged individuals
Individuals who gain weight during middle life appear to be at greater risk of developing obesity-related cancer irrespective of metabolic function and body mass index (BMI), according to a study.
Researchers examined independent and combined effects of weight gain and metabolic dysfunction during middle-adult years on obesity-related cancer risk in a cohort of 3,850 individuals (aged 45–69 years) from the Framingham Offspring Study.
Obesity-related cancer outcomes included those that involved the female reproductive organs (postmenopausal breast, uterine/endometrial and ovarian), colon, rectum, stomach, liver, gallbladder, pancreas, kidney, thyroid, oesophageal adenocarcinoma, leukaemia, non-Hodgkin lymphoma and multiple myeloma.
During about 14 years of follow up, 145 men and 90 women lost ≥0.45 kg/years (mean weight loss, –0.72 and –0.77 lbs/year, respectively), and 530 men and 805 women gained ≥0.45 kg/year (mean weight gain, 0.81 and 0.80 kg/year, respectively). Weight remained stable in 1,166 men and 1,112 women.
Compared with maintaining stable weight, gaining ≥0.45 kg/year over about 14 years was associated with a 38-percent increased cancer risk (hazard ratio [HR], 1.38; 95 percent CI, 1.09–1.76). Of note, the elevated cancer risk associated with weight gain increased by 77 percent in men and women with metabolic dysfunction (HR, 1.77; 1.21–2.59).
Compared with nonoverweight adults, men and women who became overweight (BMI ≥30 and ≥25 kg/m2, respectively) during midlife also had increased cancer risk (men: HR, 2.18; 1.33–3.56; women: HR, 1.60; 1.12–2.28).
The risk increased by 28 percent and 33 percent, although not significantly, in men and women who were already overweight at baseline. This is despite having a midlife BMI that was higher by 3.4 kg/m2 than the midlife BMI of those who gained weight later.