Fracture risk following bariatric surgery: a population-based study

Abstract

Summary The effects of bariatric surgery on skeletal health are poorly understood. We found that bariatric surgery patients are more prone to fracture when compared to the general population. While further studies of fracture risk in this population are needed, bone health should be discussed in bariatric surgery clinics. Introduction Bariatric surgery is an increasingly common treatment for medically complicated obesity. Adverse skeletal changes after bariatric surgery have been reported, but their clinical importance remains unknown. We hypothesized that bariatric surgery patients are at increased risk of fracture. Methods We conducted a historical cohort study of fracture incidence among 258 Olmsted County, Minnesota, residents who underwent a first bariatric surgery in 1985–2004. Relative fracture risk was expressed as standardized incidence ratios (SIRs), while potential risk factors were evaluated by hazard ratios (HR) obtained from a time-to-fracture regression model. Results The mean (±SD) body mass index at bariatric surgery was 49.0±8.4 kg/m2, with an average age of 44±10 years and 82 % (212) females. Gastric bypass surgery was performed in 94 % of cases. Median follow-up was 7.7 years (range, 6 days to 25 years), during which 79 subjects experienced 132 fractures. Relative risk for any fracture was increased 2.3-fold (95 % confidence interval (CI), 1.8–2.8) and was elevated for a first fracture at the hip, spine, wrist, or humerus (SIR, 1.9; 95 % CI, 1.1–2.9), as well as for a first fracture at any other site (SIR, 2.5; 95 % CI, 2.0–3.2). Better preoperative activity status was associated with a lower age-adjusted risk (HR, 0.4; 95 % CI, 0.2–0.8) while prior fracture history was not associated with postoperative fracture risk. Conclusions Bariatric surgery, which is accompanied by substantial biochemical, hormonal, and mechanical changes, is associated with an increased risk of fracture.

Effects of obesity treatments on bone mineral density, bone turnover and fracture risk in adults with overweight or obesity

“…In keeping with these findings, a population-based, historical cohort study of the medical records of 258 patients that had bariatric surgery between 1985 and 2004 found that these patients, over 94% of which had RYGB, carried a higher fracture risk than that of the general population, with an odds ratio of 2.3 (1.8-2.8) [67]. This risk was higher for fractures not only at the traditional osteoporotic sites of the hip, wrist, spine and upper arm, but also at nonosteoporotic sites such as the foot, leg or hand [67]. These two studies [66,67] are in contrast to a population-based, retrospective cohort study on 2079 surgical patients, which found no evidence of association between bariatric surgery and fracture [68].…”

“…In subgroup analysis, this association between bariatric surgery and increased fracture risk was found to be stronger with RYGB surgery than with sleeve gastrectomy or other surgery types [66]. In keeping with these findings, a population-based, historical cohort study of the medical records of 258 patients that had bariatric surgery between 1985 and 2004 found that these patients, over 94% of which had RYGB, carried a higher fracture risk than that of the general population, with an odds ratio of 2.3 (1.8-2.8) [67]. This risk was higher for fractures not only at the traditional osteoporotic sites of the hip, wrist, spine and upper arm, but also at nonosteoporotic sites such as the foot, leg or hand [67].…”

“…This risk was higher for fractures not only at the traditional osteoporotic sites of the hip, wrist, spine and upper arm, but also at nonosteoporotic sites such as the foot, leg or hand [67]. These two studies [66,67] are in contrast to a population-based, retrospective cohort study on 2079 surgical patients, which found no evidence of association between bariatric surgery and fracture [68]. However, this could be due to the fact that in this latter cohort study, over 60% of the surgical population had undergone gastric banding rather than RYGB [68].…”

“…Lower BMD is linked to a greater risk of fracture, and a significant association between bariatric surgery and fracture has been reported [66,67]. In a 12-year cohort study involving 2064 patients who underwent any of 10 types of bariatric surgery between 2001 and 2009, compared to 5027 matched controls, those that underwent bariatric surgery showed a non significant 1.41-fold increased fracture risk at 12-24 months post surgery compared to matched controls (95% confidence interval: 0.99-2.05) [66].…”

Vitamin D alteration associated with obesity and bariatric surgery

“…The risk of fracture after bariatric surgery remains a matter of controversy; a study showed twice the risk in patients who have had bariatric surgery compared to the rates of incidence based on the general population, 97 the other study showing no increase of the risk of fracture in the first two years after surgery compared to a non-operated obese population. 98 There are very many recent recommendations in clinical practice focusing on patients treated with bariatric surgery 84,99,100 (Table 1). While these recommendations are the subject of extreme care by their authors using all of the relevant and available data literature, certain recommended measures are not always based on medical data [101][102][103] A randomized study showed that taking 50,000 IU ergocalciferol weekly gave at one year higher values of 25-hydroxy vitamin D than in the daily intake of 800 IU.…”