Advertisement

Obesity, but Not Physical Activity, Is Associated With Higher Prevalence of Asymptomatic Diverticulosis

  • Rouzbeh Mashayekhi
    Affiliations
    Harvard University T.H. Chan School of Public Health, Boston, Massachusetts
    Search for articles by this author
  • Danielle R. Bellavance
    Affiliations
    Division of Gastroenterology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
    Search for articles by this author
  • Samantha M. Chin
    Affiliations
    Division of Gastroenterology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
    Search for articles by this author
  • Benjamin Maxner
    Affiliations
    Division of Gastroenterology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
    Search for articles by this author
  • Kyle Staller
    Affiliations
    Division of Gastroenterology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
    Search for articles by this author
  • Ramnik J. Xavier
    Affiliations
    Division of Gastroenterology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
    Search for articles by this author
  • Daniel C. Chung
    Correspondence
    Reprint requests Address requests for reprints to: Daniel C. Chung, MD, Gastroenterology Unit, Massachusetts General Hospital, 50 Blossom Street, GRJ704, Boston, Massachusetts 02114. fax: (617) 726-2394.
    Affiliations
    Division of Gastroenterology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
    Search for articles by this author
  • Hamed Khalili
    Correspondence
    Hamed Khalili, MD, MPH, Digestive Healthcare Center, Crohn’s and Colitis Center, Massachusetts General Hospital, 165 Cambridge Street, 9th Floor, Boston, Massachusetts 02114. fax: (978) 882-6710.
    Affiliations
    Division of Gastroenterology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts

    Clinical and Translational Epidemiology Unit, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts

    Clinical Epidemiology Unit, Karolinska Institutet, Solna, Sweden
    Search for articles by this author
Published:September 09, 2017DOI:https://doi.org/10.1016/j.cgh.2017.09.005

      Abbreviations used in this paper:

      BMI (body mass index), MET (metabolic equivalent task), OR (odds ratio)
      Colonic diverticulosis is a common condition of the large intestine diagnosed on colonoscopy.
      • Everhart J.E.
      • Ruhl C.E.
      Burden of digestive diseases in the United States part II: lower gastrointestinal diseases.
      More than 50% of people older than age 70 in the United States have diverticulosis,
      • Everhart J.E.
      • Ruhl C.E.
      Burden of digestive diseases in the United States part II: lower gastrointestinal diseases.
      with up to 20% of them experiencing complications including diverticulitis and diverticular hemorrhage.
      • Parks T.G.
      Natural history of diverticular disease of the colon.
      However, data on determinants of diverticulosis have been sparse, with prior studies on the role of obesity and physical activity showing inconsistent results.
      • Peery A.F.
      • Keku T.O.
      • Martin C.F.
      • et al.
      Distribution and characteristics of colonic diverticula in a united states screening population.
      • Peery A.F.
      • Sandler R.S.
      • Ahnen D.J.
      • et al.
      Constipation and a low-fiber diet are not associated with diverticulosis.
      • Strate L.L.
      • Liu Y.L.
      • Aldoori W.H.
      • et al.
      Physical activity decreases diverticular complications.
      • Strate L.L.
      • Liu Y.L.
      • Aldoori W.H.
      • et al.
      Obesity increases the risks of diverticulitis and diverticular bleeding.
      We therefore examined the association between obesity and physical activity, and the prevalence of diverticulosis.

      Methods

      We used a colonoscopy-based longitudinal cohort, the GI Disease and Endoscopy Registry (GIDER), at the Massachusetts General Hospital. Average-risk participants older than age 18 undergoing a routine screening colonoscopy who did not have serious gastrointestinal diseases were invited to complete a detailed questionnaire on lifestyle and medical diagnoses before their colonoscopy procedure.
      Data on body mass index (BMI) were derived from the participant’s measured weight and height at baseline. We evaluated physical activity by asking participants about the average time per week spent during the past year doing various activities and a metabolic equivalent task (MET) was assigned to each activity based on previously established guidelines.
      • Ainsworth B.E.
      • Haskell W.L.
      • Leon A.S.
      • et al.
      Compendium of physical activities: classification of energy costs of human physical activities.
      We determined the average MET-h/wk for each participant and categorized physical activity into 3 categories (<9.0, 9.0–26.9, and ≥27.0 MET-h/wk) corresponding to less than 3.0, 3.0 to 8.9, and 9.0 or more hours per week spent walking, respectively. Our primary outcome was defined as the presence of diverticulosis detected during the colonoscopy by the endoscopist. We used logistic regression modeling to calculate the adjusted odds ratios (ORs) and 95% CIs.

       Ethical Approval

      The study was approved by the Partners Human Research Committee (Institutional Review Board).

      Results

      Among 223 participants enrolled in the GI Disease and Endoscopy Registry with a mean age of 60.8 years (SD, 9.8 y), we confirmed diverticulosis among 86 (38.6%). Overall, the majority of participants were white (92.8%) and nonsmokers (63.7%), and 39.5% and 32.3% were overweight (25.0–29.9 kg/m2) or obese (≥30.0 kg/m2), respectively. The rates of diverticulosis varied from 22.2% in the normal BMI group to 48.6% in the obese group (Table 1). The prevalence of diverticulosis appeared to increase with a higher BMI (Ptrend = .003). Compared with participants with a normal BMI, the multivariable adjusted ORs of diverticulosis were 3.02 (95% CI, 1.33–6.88) and 4.43 (95% CI, 1.88–10.49) among participants with a BMI of 25.0 to 29.9 kg/m2 and 30.0 kg/m2 or greater, respectively.
      Table 1Obesity and Physical Activity and Prevalence of Diverticulosis
      Body mass index, kg/m2Physical activity, MET-h/wk
      <25.025.0–29.9≥30.0<9.09.0–26.9≥27.0
      Cases, n (%)14 (22.2)37 (42.1)35 (48.6)32 (50.0)24 (36.9)30 (31.9)
      Age adjusted1.002.48 (1.16–5.31)3.94 (1.77–8.73)1.000.55 (0.27–1.15)0.51 (0.26–1.01)
      Model 2
      Adjusted for age (y), physical activity (MET-h/wk), and BMI (kg/m2).
      1.002.45 (1.14–5.25)3.81 (1.69–8.61)1.000.59 (0.28–1.25)0.70 (0.34–1.43)
      Model 3
      Adjusted for age (y), physical activity (MET-h/wk), BMI (kg/m2), dietary pattern (Western standard diet, low-red-meat diet, no-red-meat diet), and smoking (yes, no).
      1.002.90 (1.31–6.45)4.51 (1.93–10.56)1.000.58 (0.27–1.25)0.69 (0.33–1.43)
      Fully adjusted
      Adjusted for age (y), physical activity (MET-h/wk), BMI (kg/m2), dietary pattern (Western standard diet, low-red-meat diet, no-red-meat diet), smoking (yes, no), and number of bowel movements (<1/d, 1/d, or >1/d).
      1.003.02 (1.33–6.88)4.43 (1.88–10.49)1.000.57 (0.26–1.24)0.63 (0.30–1.33)
      NOTE. OR (95% CI) is shown unless otherwise indicated.
      a Adjusted for age (y), physical activity (MET-h/wk), and BMI (kg/m2).
      b Adjusted for age (y), physical activity (MET-h/wk), BMI (kg/m2), dietary pattern (Western standard diet, low-red-meat diet, no-red-meat diet), and smoking (yes, no).
      c Adjusted for age (y), physical activity (MET-h/wk), BMI (kg/m2), dietary pattern (Western standard diet, low-red-meat diet, no-red-meat diet), smoking (yes, no), and number of bowel movements (<1/d, 1/d, or >1/d).
      We confirmed diverticulosis among 50% of participants in the lowest category of physical activity (<9 MET-h/wk), 36.9% of participants with 9.0 to 26.9 MET-h/wk, and 31.9% of those with 27.0 or more MET-h/wk. In multivariable analysis, we observed a nonsignificant inverse association between physical activity and the prevalence of diverticulosis (Ptrend = .13). Compared with participants with fewer than 9 MET-h/wk, the multivariable adjusted ORs of diverticulosis were 0.57 (95% CI, 0.26–1.24) and 0.63 (95% CI, 0.30–1.33) among the 9.0 to 26.9 and 27.0 or more MET-h/wk groups, respectively.
      We also examined the association between BMI and the risk of diverticulosis according to strata defined by age, location (left sided vs pancolonic), smoking, and physical activity and observed no effect modification (P for interaction > .35).

      Discussion

      In this colonoscopy-based cohort, obesity, as measured by BMI, was associated significantly with an increased prevalence of colonic diverticulosis even after adjusting for traditional risk factors. Although the prevalence of diverticulosis was lower among individuals with higher amounts of physical activity, the risk did not reach statistical significance.
      Our finding that obesity is associated with an increased prevalence of diverticulosis is supported by 2 prior colonoscopy-based studies.
      • Peery A.F.
      • Keku T.O.
      • Martin C.F.
      • et al.
      Distribution and characteristics of colonic diverticula in a united states screening population.
      • Peery A.F.
      • Sandler R.S.
      • Ahnen D.J.
      • et al.
      Constipation and a low-fiber diet are not associated with diverticulosis.
      Because these studies had limited information on several key risk factors including smoking, number of bowel movements, and dietary patterns, our analysis, which adjusted carefully for them, significantly extends these findings. In contrast, several studies have shown no significant associations between obesity and diverticulosis. However, these studies were limited by relying on self-reported diagnosis, which may lead to misclassification and under-reporting,
      • Strate L.L.
      • Liu Y.L.
      • Aldoori W.H.
      • et al.
      Obesity increases the risks of diverticulitis and diverticular bleeding.
      or they were conducted in East Asian countries where the prevalence of obesity and diverticulosis are significantly lower.
      • Nagata N.
      • Sakamoto K.
      • Arai T.
      • et al.
      Visceral abdominal obesity measured by computed tomography is associated with increased risk of colonic diverticulosis.
      The primary strengths of our study included the prospective collection of lifestyle data, ascertaining diverticulosis by colonoscopy, and the ability to adjust for important lifestyle factors. We acknowledge that our study participants were mostly white and from a single center and although we used a validated method to measure physical activity, there may have been measurement errors, accounting for a lack of observed association.
      In this colonoscopy-based cohort, we found that obesity is associated with an increased prevalence of colonic diverticulosis. Although our observed associations do not imply causation, our results highlight the potential role of obesity in the pathogenesis of diverticulosis. Given that the US population is aging and experiencing an obesity epidemic, we believe that the rates of diverticulosis will continue to increase, and, therefore, further research into understanding the obesity-related pathway that may mediate this association is warranted.

      References

        • Everhart J.E.
        • Ruhl C.E.
        Burden of digestive diseases in the United States part II: lower gastrointestinal diseases.
        Gastroenterology. 2009; 136: 741-754
        • Parks T.G.
        Natural history of diverticular disease of the colon.
        Clin Gastroenterol. 1975; 4: 53-69
        • Peery A.F.
        • Keku T.O.
        • Martin C.F.
        • et al.
        Distribution and characteristics of colonic diverticula in a united states screening population.
        Clin Gastroenterol Hepatol. 2016; 14: 980-985
        • Peery A.F.
        • Sandler R.S.
        • Ahnen D.J.
        • et al.
        Constipation and a low-fiber diet are not associated with diverticulosis.
        Clin Gastroenterol Hepatol. 2013; 11: 1622-1627
        • Strate L.L.
        • Liu Y.L.
        • Aldoori W.H.
        • et al.
        Physical activity decreases diverticular complications.
        Am J Gastroenterol. 2009; 104: 1221-1230
        • Strate L.L.
        • Liu Y.L.
        • Aldoori W.H.
        • et al.
        Obesity increases the risks of diverticulitis and diverticular bleeding.
        Gastroenterology. 2009; 136: 115-122.e1
        • Ainsworth B.E.
        • Haskell W.L.
        • Leon A.S.
        • et al.
        Compendium of physical activities: classification of energy costs of human physical activities.
        Med Sci Sports Exerc. 1993; 25: 71-80
        • Nagata N.
        • Sakamoto K.
        • Arai T.
        • et al.
        Visceral abdominal obesity measured by computed tomography is associated with increased risk of colonic diverticulosis.
        J Clin Gastroenterol. 2015; 49: 816-822