Association between gastrectomy and the risk of type 2 diabetes in gastric cancer survivors: A nationwide cohort study.

Postprandial glycemic fluctuations after gastrectomy are seen in patients with gastric cancer but, no studies have investigated the association between gastrectomy and type 2 diabetes mellitus (T2DM) in gastric cancer survivors. This study aimed to elucidate the relationship between gastrectomy (total or subtotal) and incident T2DM. In addition, we explored whether vitamin B12 supplementation modulates this risk among patients who have undergone total gastrectomy. In this large nationwide population-based retrospective cohort study using the National Health Insurance Service database of South Korea, we identified patients aged >20 years who underwent gastrectomy from 2008 to 2015 (n = 150,074) and age- and sex-matched controls without gastrectomy (n = 301,508). A Cox proportional hazards model was used. During the median follow-up duration of 4.4 years after the 2-year time lag after gastrectomy, of the 78,006 subjects, 4,597 (5.9 %) developed T2DM. Compared with matched controls, the adjusted hazard ratio (AHR[95 % confidence interval]) for T2DM of patients with total gastrectomy was 1.34[1.23;1.47]. The corresponding AHR after subtotal gastrectomy was 0.81[0.76;0.86]. Among the patients with total gastrectomy, the risk of T2DM was significantly increased in those who did not receive any vitamin B12 supplementation (AHR=1.60[1.33;1.92]), whereas the risk of T2DM was lower (close to being statistically significant) in those who received continuous vitamin B12 supplementation after gastrectomy (AHR=0.70[0.49;1.01]). These results show a significantly reduced risk of T2DM in gastric cancer patients undergoing subtotal gastrectomy and a significantly increased risk of T2DM in gastric cancer patients undergoing total gastrectomy, which is mitigated by continuous vitamin B12 supplementation.

Kim G ，Han KD ，Cho SH ，Oh R ，Lee YB ，Jin SM ，Hur KY ，Kim JH ... -  《-》

Risk of Dementia in Gastric Cancer Survivors Who Underwent Gastrectomy: A Nationwide Study in Korea.

Choi YJ ，Shin DW ，Jang W ，Lee DH ，Jeong SM ，Park S ，Han KD ，Park YG ... -  《-》

Increased Risk of Osteoporotic Fracture in Postgastrectomy Gastric Cancer Survivors Compared With Matched Controls: A Nationwide Cohort Study in Korea.

Shin DW ，Suh B ，Lim H ，Suh YS ，Choi YJ ，Jeong SM ，Yun JM ，Song SO ，Park Y ... -  《-》

Gastrectomy, vitamin B12 supplementation and the risk of Parkinson's disease: A nationwide cohort study.

Previous evidence has suggested roles for α-synuclein propagation and vitamin B12 (VitB12) deficiency in the pathogenesis of Parkinson's disease (PD). We investigated whether gastric cancer (GC) patients who underwent gastrectomy had a lower risk of PD and whether VitB12 supplementation modified the risk. GC patients aged ≥50 years who underwent curative gastrectomy between 2007 and 2012 (n = 72,216) and matched comparison groups (n = 211,389) were identified from the Korean National Health Insurance database. The risks of PD were analyzed by Cox regression. Compared to their matched comparison groups, GC patients who underwent gastrectomy showed a decreased risk of PD (adjusted HR [aHR] 0.86; 95% confidence interval [CI] 0.75-0.98), but the significance disappeared after further adjustment with smoking and body mass index (BMI). To elaborate, subtotal gastrectomy (STG) was associated with decreased risk of PD (aHR 0.85; 95% CI 0.74-0.99) while total gastrectomy (TG) was not (aHR 0.89; 95% CI 0.66-1.19), although the risk reduction was not significant when further adjusted for smoking and BMI. Among the patients who underwent TG, their risk of PD was markedly lower when they had VitB12 supplementation after surgery (aHR 0.36; 95% CI 0.17-0.76), while the risk was higher when they did not have any (aHR 1.55; 95% CI 1.03-2.32). GC patients who underwent gastrectomy and received uninterrupted VitB12 supplementation had a decreased incidence of PD. This study provides indirect epidemiological evidence for the potential roles of gastrectomy and VitB12 in the pathogenesis of PD.

Choi YJ ，Choi IY ，Jang W ，Jeong SM ，Park S ，Han K ，Lee Y ，Lee DH ，Shin DW ... -  《-》

The association between weight change after gastric cancer surgery and type 2 diabetes risk: A nationwide cohort study.

Although gastric cancer patients generally experience drastic weight decrease post-gastrectomy, the impact of weight decrease on type 2 diabetes risk remains unclear. We investigated the type 2 diabetes risk after gastric cancer surgery according to postoperative weight decrease in gastric cancer survivors in South Korea, the country with the world's highest rate of gastric cancer survival. This retrospective nationwide cohort study included gastric cancer surgery recipients between 2004 and 2014 who survived for ≥5 years post-surgery. We included patients without a history of diabetes at the time of surgery and those who had not received adjuvant chemotherapy before or after the surgery. Postoperative weight loss was defined as the per cent body weight loss at 3 years post-surgery compared with the baseline. The type 2 diabetes risk was evaluated using Cox regression analyses for five groups of postoperative weight decrease. In 5618 included gastric cancer surgery recipients (mean age, 55.7 [standard deviation, SD, 10.9] years; 21.9% female; mean body mass index, 23.7 [SD, 2.9] kg/m2 ), 331 patients (5.9%) developed postoperative type 2 diabetes during follow-up duration of 8.1 years (median; interquartile range, 4.8 years; maximum, 15.2 years). Compared with those who gained weight post-surgery, patients with ≥ -15% to < -10% of postoperative weight decrease (hazard ratio, 0.65; 95% confidence interval, 0.49-0.87; P = 0.004) had the lowest type 2 diabetes risk. A non-linear association occurred between postoperative weight decrease and the type 2 diabetes risk in gastrectomy recipients (Akaike's information criterion [AIC] for non-linear model, 5423.52; AIC for linear model, 5425.61). A U-shaped non-linear association occurred between the type 2 diabetes risk and postoperative weight decrease in gastric cancer survivors who underwent gastrectomy. The lowest type 2 diabetes risk occurred in patients with ≥ -15% to < -10% of postoperative weight decrease at 3 years.

Kwon Y ，Ha J ，Kim D ，Hwang J ，Park SH ，Kwon JW ，Park S ... -  《-》