Department of Surgery, Mayo Clinic Florida, 4500 San Pablo Rd, Davis 3 N, Jacksonville, FL, 32256, USA.
Surg Endosc. 2020 Jul;34(7):3184-3190. doi: 10.1007/s00464-019-07090-5. Epub 2019 Sep 13.
The respiratory coefficient (RQ), as determined by indirect calorimetry (IC), classifies diet as being carbohydrate rich (RQ = 0.7-0.8), fat rich (RQ = 0.9-1.0), or overfeeding (RQ > 1). We hypothesized that preoperative RQ may be associated with weight-loss outcomes after bariatric surgery.
From 2016 to 2018, 137 obese patients were enrolled in a Bariatric Registry and underwent dietary and behavioral counseling, followed by preoperative IC. Resting energy expenditure (REE) and RQ of all patients was measured. Patients were classified as over-feeders (OF; 42, 31%) with RQ > 1 or non-over-feeders (NOF; 95, 69%) with RQ < 1. At baseline, there was no difference between groups in gender [female: 105 (76.6%), male: 32 (23.4%)], body mass index (BMI; OF: 46.8 ± 7.8 vs. NOF: 44.8 ± 7.4 kg/m, p = 0.40), or baseline REE (OF: 1897 ± 622 vs. NOF: 1874 ± 579, p = 0.74), although OF were younger [mean age (OF: 47.1 ± 13.0 years vs. NOF: 43.1 ± 13.4; p = 0.009). At 6-month follow-up 94 patients [53.28%; OF: 35 (83%) vs. NOF: 59 (62%), p = 0.016] were seen and 48 [35.03%; OF: 23 (55%) vs. NOF: 25 (59%), p = 0.001] at 12-month follow-up. On preoperative psychological assessment, OF had a significantly higher rate of childhood neglect (OF: 28 (47.46%) vs. NOF: 40 (28.99%); p = 0.01).
At 1 year postoperatively, the OF had a significantly higher BMI (OF: 34.3 ± 6.5 vs. NOF: 29.3 ± 5.1 kg/m, p = 0.009). Differences in weight were not significant at 6-month (OF: 36.0 ± 6.5 vs. NOF: 33.5 ± 5.9 kg/m, p = 0.07). There was no difference between type of operation and RQ group (RYGB; OF: 55 (75%) vs. NOF: 18 (25%) and SG; OF: 40 (62%) vs. NOF: 24 (38%), p = 0.14), nor in BMI loss after operation.
Evidence of overfeeding in the preoperative period prior to bariatric surgery is associated with higher resultant BMI at 1 year. Calculation of the RQ with IC has prognostic significance in bariatric surgery, and calculation of REE based on assumed normal RQ potentiates error. It is unclear if overfeeding is purely behavioral or secondary to potentially reversible metabolic etiology.
通过间接测热法（IC）确定的呼吸系数（RQ）将饮食分类为富含碳水化合物（RQ=0.7-0.8）、富含脂肪（RQ=0.9-1.0）或过度喂养（RQ>1）。我们假设术前 RQ 可能与减重手术后的体重减轻结果有关。
2016 年至 2018 年，137 名肥胖患者入组了减重登记处，并接受了饮食和行为咨询，随后进行了术前 IC。所有患者的静息能量消耗（REE）和 RQ 均进行了测量。患者被分为过度喂养者（OF；42 例，31%），RQ>1 或非过度喂养者（NOF；95 例，69%），RQ<1。基线时，两组在性别[女性：105（76.6%），男性：32（23.4%）]、体重指数（BMI；OF：46.8±7.8 vs. NOF：44.8±7.4 kg/m，p=0.40）或基线 REE（OF：1897±622 vs. NOF：1874±579，p=0.74）方面无差异，尽管 OF 组年龄更小[平均年龄（OF：47.1±13.0 岁 vs. NOF：43.1±13.4 岁；p=0.009）。在 6 个月的随访中，94 名患者[53.28%；OF：35（83%）vs. NOF：59（62%），p=0.016]和 48 名患者[35.03%；OF：23（55%）vs. NOF：25（59%），p=0.001]在 12 个月的随访中。在术前心理评估中，OF 组有更高的童年忽视率（OF：28（47.46%）vs. NOF：40（28.99%）；p=0.01）。
术后 1 年，OF 组 BMI 明显更高（OF：34.3±6.5 vs. NOF：29.3±5.1 kg/m，p=0.009）。在 6 个月时，体重差异无统计学意义（OF：36.0±6.5 vs. NOF：33.5±5.9 kg/m，p=0.07）。手术类型和 RQ 组（RYGB；OF：55（75%）vs. NOF：18（25%）和 SG；OF：40（62%）vs. NOF：24（38%），p=0.14）之间，以及术后 BMI 下降均无差异。
减重手术前术前过度喂养的证据与 1 年后更高的 BMI 结果相关。IC 计算的 RQ 在减重手术中有预后意义，基于假设的正常 RQ 计算 REE 会增加误差。目前尚不清楚过度喂养是纯粹的行为问题还是潜在可逆转的代谢病因所致。
