Association Between Body Mass Index and Quality of Split Bowel Preparation

Abstract

Background and Aims Little is known about the association between obesity and bowel preparation. We investigated whether body-mass index (BMI) is an independent risk factor for inadequate bowel preparation in patients who receive split preparation regimens. Methods We performed a retrospective study of data from 2163 consecutive patients (mean age, 60.6 ± 10.5 y; 93.8% male) who received outpatient colonoscopies in 2009 at the Veterans Affairs Medical Center in Indianapolis, Indiana. All received a split preparation, categorized as adequate (excellent or good, based on the Aronchick scale) or inadequate. We performed multivariable analysis to identify factors independently associated with inadequate preparation. Results Bowel preparation quality was inadequate for 44.2% of patients; these patients had significantly higher mean BMIs than patients with adequate preparation (31.2±6.5 vs 29.8±5.9, respectively; P<.0001) and Charlson comorbidity scores (1.5±1.6 vs 1.1±1.4; P<.0001). Independent risk factors for inadequate preparation were BMI ≥ 30 kg/m2 (odds ratio [OR], 1.46; 95% confidence interval [CI], 1.21–1.75; P <.0001), use of tobacco (OR, 1.28; 95% CI, 1.07–1.54; P=.0084) or narcotics (OR, 1.28; 95% CI, 1.04–1.57; P=.0179), hypertension (OR, 1.30; 95% CI, 1.07–1.57; P=.0085), diabetes (OR, 1.38; 95% CI, 1.12–1.69; P=.0021), and dementia (OR, 3.02; 95% CI, 1.22–7.49; P=.0169). Conclusions BMI is an independent factor associated with inadequate split bowel preparation for colonoscopy. Additional factors associated with quality of bowel preparation include diabetes, hypertension, dementia, and use of tobacco and narcotics. Patients with BMIs ≥ 30 kg/m2 should be considered for more intensive preparation regimens.

Optimizing bowel preparation for colonoscopy: what are the predictors of an inadequate preparation?

“…Furthermore, our results did not demonstrate other positive associations reported in previous studies, such as BMI, 7,8 prolonged PC interval, 15-16 tobacco use, 8 and hypertension. 8 One explanation is that our population had a much lower rate of inadequate preparations (8.5%) compared with most studies, which report an inadequacy rate of 20% to 44%.…”

“…11 We were able to demonstrate an increased risk of an inadequate preparation with opioids use (Table 4), which supports previous findings. 7,8 However, similar to Ness et al, our analysis did not support a relationship between medical conditions associated with gut hypomotility (hypothyroidism and diabetes) and an inadequate bowel preparation. There was also a lack of association between patient-reported constipation and inadequate preparations.…”

“…8 One explanation is that our population had a much lower rate of inadequate preparations (8.5%) compared with most studies, which report an inadequacy rate of 20% to 44%. 1,[3][4][5][6]8 The salient question here is: why was the preparation adequacy rate in our population much higher than other studies that used similar bowel cleansing regimens? We believe that the main contributing factor is the comprehensive patient education sessions that all patients received.…”

“…Although our population with stroke or dementia is small, our results support the findings of previous studies. [6][7][8] Complications associated with stroke and dementia can include difficulties in swallowing, problems with mobility, as well as comprehending and adhering to preparation instructions. We believe that these patients may benefit from a multidisciplinary pre-endoscopic assessment and an individualized approach to address their specific difficulties.…”

“…These factors include age, 4,5 sex, 3,4,6,7 body mass index (BMI) 4,7,8 diabetes, 4,5,7,8 stroke and dementia, [6][7][8] ;and medications, such as tricyclic antidepressants (TCAs), calcium channel blockers (CCBs), and opioids. [6][7][8][9][10][11][12][13][14] However, many studies enrolled small cohorts, were single-centered studies, and methodologies varied greatly. There was also little mention of patient education, which is a factor that could play an important role in determining the quality of bowel cleanse.…”