Journal of Clinical Medicine Article Genetic Testing to Predict Weight Loss and Diabetes Remission and Long-Term Sustainability after Bariatric Surgery: A Pilot Study Andreea Ciudin 1,2, *,† , Enzamaria Fidilio 1,† , Angel Ortiz 1 , Sara Pich 3 , Eduardo Salas 3 , Jordi Mesa 1,2 , Cristina Hernández 1,2 , Olga Simó-Servat 1,2 , Albert Lecube 2,4 and Rafael Simó 1,2, * 1 Institut de Recerca Vall d’Hebron, Universitat Autònoma de Barcelona (VHIR-UAB), 08035 Barcelona, Spain 2 CIBER de Diabetes y Enfermedades Metabólicas Asociadas, Instituto de Salud Carlos III, 08950 Barcelona, Spain 3 Scientific Department, Gendiag.exe, Joan XXIII, 10, Esplugues de LLobregat, 08950 Barcelona, Spain 4 Endocrinology and Nutrition Department, Hospital Universitari Arnau de Vilanova, IRBLleida, Universitat de Lleida, 25198 Lleida, Spain * Correspondence: aciudin@vhebron.net (A.C.); rafael.simo@vhir.org (R.S.); Tel.: +34-934894172 (A.C. & R.S.); Fax: +34-934894032 (A.C. & R.S.) † Theses authors have contributed equally to this work. Received: 26 June 2019; Accepted: 28 June 2019; Published: 3 July 2019 Abstract: Introduction: The aim of this pilot study was to assess genetic predisposition risk scores (GPS) in type 2 diabetic and non-diabetic patients in order to predict the better response to bariatric surgery (BS) in terms of either weight loss or diabetes remission. Research Design and Methods: A case-control study in which 96 females (47 with type 2 diabetes) underwent Roux-en-Y gastric by-pass were included. The DNA was extracted from saliva samples and SNPs were examined and grouped into 3 GPS. ROC curves were used to calculate sensitivity and specificity. Results: A highly sensitive and specific predictive model of response to BS was obtained by combining the GPS in non-diabetic subjects. This combination was different in diabetic subjects and highly predictive of diabetes remission. Additionally, the model was able to predict the weight regain and type 2 diabetes relapse after 5 years’ follow-up. Conclusions: Genetic testing is a simple, reliable and useful tool for implementing personalized medicine in type 2 diabetic patients requiring BS. Keywords: diabetes; obesity; bariatric surgery 1. Introduction Obesity represents a major public health problem and it is associated with a significant economic burden on the health systems of developed countries, mainly due to the associated co-morbidities. Among these co-morbidities, type 2 diabetes (T2D) is one of the most important. Bariatric surgery (BS) is a successful treatment for morbid obesity and leads to a dramatic improvement in obesity-related comorbidities [1]. The remission rate of T2D after BS is around 60–70% after 1 year of follow-up [2]. Therefore, there is a significant proportion of non-responders to BS in terms of diabetes remission. Additionally, after 5 years, there is about a 20–35% relapse of T2D after Y-de-Roux gastric by-pass (RYGB) [3–5]. A score based on clinical variables for the pre-operative prediction of T2D remission following RYGB surgery (DiaRem) was proposed [6]. However, this model has several limiting factors [7] and it has not been generally adopted in clinical practice. At present, there are no reliable predictors of T2D remission and relapse after BS. J. Clin. Med. 2019, 8, 964; doi:10.3390/jcm8070964 www.mdpi.com/journal/jcm J. Clin. Med. 2019, 8, 964 2 of 8 In recent years, interest in the genetic influence on the response of different treatments for obesity has increased. Two retrospective studies [8,9] showed that several single nucleotide polymorphisms (SNPs) were associated with a poor response to BS. However, in these studies the discrimination capacity of the GPS was not significant, and the role of T2D in the response to BS and the impact of these genetic factors on diabetes remission were not evaluated. On this basis, the aim of the present study was to evaluate whether genetic markers can be used for the prediction of adequate weight loss and diabetes remission after BS. 2. Material and Methods A single-center, retrospective observational pilot study in a third-level university hospital (Vall d´Hebron University Hospital, Barcelona, Spain) was conducted following the Strengthening the Reporting of Observational Studies in Epidemiology guidelines. The study comprised patients that underwent RYBG surgery between January 2010 and December 2012. The inclusion criteria were women, stable weight in the prior 6 months before BS, and minimum of 5 years of follow-up after BS. In order to avoid heterogeneity and given that the vast majority of the patients under bariatric surgery were women, we decided to rule out the inclusion of men in this pilot study. The patients were informed about the study and they all signed the written informed consent form. The exclusion criteria were male, marked mobility problems, a different BS technique apart from RYBG, and severe psychiatric or eating disorders. For the genetic study, a sample of saliva was collected. The characteristics of RYBG were food loop length: 150–180 cm, and bilio-pancreatic loop length: 120 cm, gastric pouch 30 cc3 . The technique was the same in all cases, performed by the same surgical team in our hospital. Excess body weight (EBW) was defined as the amount of weight that was in excess of the ideal body weight (IBW). The percentage of excess weight loss (EWL) was calculated according to the formula: %EWL = (weight before BS (kg) − weight after BS (kg)/EBW(kg)) × 100. The post-BMI weight regain was defined as a 10% regain of the minimal weight after BS. The minimal weight after BMI was achieved at 2 years follow-up for all of the patients. Diabetes remission was defined according to American Diabetes Association (ADA) criteria [10]. Relapse of T2D was defined as one or more of the following conditions: (a) restarting diabetes medication; (b) one or more HbA1c measures ≥ 6.5%; and/or (c) one or more fasting glucose measures ≥ 126 mg/dL [11]. The study was approved by the Local Ethics Committee and registered at Clinical.Trials.gov, NCT02405949. 2.1. Genotyping and Sequencing The DNA was extracted from saliva samples and processed by GoldenGate® Genotyping Assay for VeraCode. The genetic predisposition was assessed using Nutri inCode (NiC) (Ferrer inCode) and selecting the 57 SNPs associated with susceptibility to diabetes, obesity, appetite regulation, weight loss in response to hypocaloric diet, and the response to BS. The details about the SNPs are reflected in the Supplementary Materials. The selected SNPs were grouped into three genetic predisposition risk scores (GPS): diabetes remission, weight loss in non-diabetic subjects, and weight loss in subjects with diabetes. 2.2. Statistical Analysis In order to assess the best predictive GPS, patients were distributed into 4 subgroups according to the BS response (%EWL) and the presence of T2D: (1) %EWL < 40% without diabetes (n = 15); (2) %EWL < 40% with diabetes (n = 16); (3) %EWL > 75% without diabetes (n = 35); and (4) T2D and %EWL > 75% with diabetes (n = 31). Univariate and multivariate logistic regressions were used to establish associations. Akaike Information Criterion (AIC)-based backward selection was used to remove insignificant terms from an initial model containing all the candidate predictors. The calibration J. Clin. Med. 2019, 8, 964 3 of 8 of the model’s adequacy was determined by the Hosmer–Lemeshow test. The area under the ROC curve (AUROC) was used for evaluating the prediction performance of the models. The cut-offs for the developed algorithms were selected as the point which maximizes the Youden index. J. Clin. Med. 2019, 8, x FOR PEER REVIEW 3 of 8 3. Results the ROC curve (AUROC) was used for evaluating the prediction performance of the models. The The clinical cut-offs characteristics for the of the patients developed algorithms included were selected inpoint as the the study whichare shown the maximizes in Table Youden1. index. Apart from age, we did not find any significant differences between diabetic and non-diabetic subjects before 3. Results BS. The diabetic treatment received by subjects with diabetes is displayed in Figure 1. No other medicationThe clinical apart fromcharacteristics of the patients AINEs occasionally and included vitamin in the study areasshown supplements in Table after per protocol 1. Apart bariatric from age, we did not find any significant differences between diabetic and non-diabetic surgery (ciancobalamin 1000 mcg/month, colecalciferol 25.000–100.000 UI/month) were administered. subjects before BS. The diabetic treatment received by subjects with diabetes is displayed in Figure 1. No other medication apart Table from AINEs 1. Baseline occasionally characteristics andpatients of the vitaminincluded supplements in the as per protocol after study. bariatric surgery (ciancobalamin 1000 mcg/month, colecalciferol 25.000–100.000 UI/month) were administered. Non-Diabetic Patients Type 2 Diabetic Patients p N 50 47 Table 1. Baseline characteristics of the patients included in the study. Age (years) 48.0 (37.5; 55.0) 52.0 (46.0; 58.8) 0.0016 Initial BMI (Kg/m2 ) 45.2 (43.0; 48.5) Patients Type Non-Diabetic 42.5 (40.1; 46.4) 2 Diabetic Patients p 0.008 BMI (Kg/m2 ) 2 y post-BS N 31.8 (26.1; 35.6) 50 30.9 (26.8;47 35.7) n.s. 5 y post-BS Age (Kg/m2 ) BMI(years) 32.63 (21; 48.052.14) (37.5; 55.0) 33.68 52.0 (21; (46.0;46.43) 58.8) 0.0016 n.s. HypertensionInitial (%)BMI (Kg/m2) 45.2 (43.0; 48.5) 48.3 42.5 49.5 (40.1; 46.4) 0.008 n.s. Dyslipidemia post-BS BMI (Kg/m2) 2 y (%) 31.8 (26.1; 35.6) 43.2 30.9 45.7 (26.8; 35.7) n.s. n.s. 5 y Sleep apnea (%) post-BS BMI (Kg/m2) 32.63 (21; 52.14) 27.2 33.6829.7 (21; 46.43) n.s. n.s. Hypertension (%) 48.3 49.5 n.s. Dyslipidemia (%) 43.2 45.7 n.s. In the subgroup of the Sleep apnea (%) non-diabetic patients, 27.2 the multivariate 29.7logistic regression equation for n.s. predicting positive weight loss response (%EWL > 75%) after the BS (NiC-Bariatric-ND) includes In the subgroup SNPs associated of theloss with weight non-diabetic patients, in response the multivariate to a hypocaloric dietlogistic regression and SNPs equation associated to for appetite predicting positive weight loss response (%EWL > 75%) after the BS (NiC-Bariatric-ND) includes regulation. The model showed an AUROC of 0.763 (95% CI 0.605 to 0.920; p < 0.001), a sensitivity of SNPs associated with weight loss in response to a hypocaloric diet and SNPs associated to appetite 86.49%, and a specificity of 57.14%. The calibration of the adequacy of the model determined by the regulation. The model showed an AUROC of 0.763 (95% CI 0.605 to 0.920; p < 0.001), a sensitivity of Hosmer–Lemeshow test wasof0.679. 86.49%, and a specificity 57.14%. The calibration of the adequacy of the model determined by the The continuous variables Hosmer–Lemeshow test waswere 0.679.median (1st quartile; 3rd quartile) and the categorical data were percentages. TheBMI: body mass continuous index. variables wereEWL: excess median of weight (1st quartile; 3rdloss. BS: and quartile) bariatric surgery.data the categorical Hypertension were percentages. was defined BMI: body by increased mass index. systolic (≥140 EWL: mmHg) excess of weight loss. or increased BS: bariatric diastolic surgery. (≥90 mmHg) Hypertension blood pressure or by the usewas defined by increased of antihypertensive systolic drugs, (≥140 mmHg) according or increased to current diastolic guidelines. (≥90 mmHg)was Dyslipidemia blood pressure defined byorthe use by the use of antihypertensive drugs, according to current guidelines. Dyslipidemia was defined by of lipid-lowering drugs, decreased values of HDL cholesterol (men < 0.9 mmol/L, women < 1.0 mmol/L) the use of lipid-lowering drugs, decreased values of HDL cholesterol (men < 0.9 mmol/L, women < or by at least one increased value of total cholesterol (>5.2 mmol/L), LDL cholesterol or triglycerides 1.0 mmol/L) or by at least one increased value of total cholesterol (>5.2 mmol/L), LDL cholesterol or (>1.7 mmol/L). triglycerides (>1.7 mmol/L). 14 12 Diet 10 Diet+metformin 8 Diet+SU Diet+iDPPIV+Metformin 6 Diet+iDPPIV 4 Diet+GLP-1AR+Metformin 2 Diet+GLP-1AR 0 Number of patients FigureFigure 1. 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