title: Early changes in respiratory quotient and resting energy expenditure predict later weight changes in patients treated for poorly controlled type 2 diabetes.
abstract: OBJECTIVE
  This study looked at whether early changes in resting energy expenditure (REE) and respiratory quotient (RQ) are correlated with later weight changes in patients with type 2 diabetes (T2D) being treated with insulin or GLP-1 analogues, or diet.
  
  
  METHODS
  A total of 67 patients (age: 57 ± 9 years; BMI: 33.7 ± 5.0 kg/m(2); HbA1c: 9.9 ± 1.5%) began taking an insulin analogue at bedtime (INS, n=28; initial dose: 0.2 IU/kg) or a GLP-1 analogue (GLP-1, n=23), or only a dietary intervention (diet, n=16; restricted carbohydrates and calories). Their respiratory exchanges were monitored on days 0, 1 and 2 before breakfast.
  
  
  RESULTS
  Two days after starting the bedtime insulin analogue, fasting glycaemia improved (INS: -65 ± 41 mg/dL; GLP-1: -29 ± 48 mg/dL; diet: -31 ± 46 mg/dL; P<0.05), REE decreased (INS: -162 ± 241 kcal/24h; GLP-1: 0 ± 141 kcal/24h; diet: -41 ± 154 kcal/24h; P<0.05) and RQ increased (from 0.76 ± 0.04 to 0.80 ± 0.04; P<0.01), whereas only RQ decreased with diet (from 0.79 ± 0.05 to 0.76 ± 0.04; P<0.05) and remained unchanged with GLP-1 (P<0.005 for ΔRQ across treatments). Only 33 patients attended the scheduled examination three months later. HbA1c improved (INS, n=16: -1.7 ± 1.4%; GLP-1, n=12: -2.1 ± 1.4%; diet, n=5: -1.7 ± 2.8%; NS), while weight changes differed (INS: +1.5 ± 4.3 kg; GLP-1: -2.8 ± 2.8 kg; diet: -2.2 ± 2.7 kg; P<0.005). After three months, weight changes correlated with early changes in REE (r=-0.37, P<0.05) and RQ (r=+0.43, P<0.01), and remained correlated when both changes were included in a multivariate regression analysis (r=0.58, P<0.005).
  
  
  CONCLUSIONS
  In poorly controlled patients with T2D and two days after the introduction of a bedtime insulin analogue, REE decreased by -9% while RQ increased by +5%, pointing to a reduction of lipid oxidation. These changes were predictive of later weight gain.
authors.affiliation: Nutrition-diabétologie, CHU de Bordeaux, avenue de Magellan, 33600 Pessac, France; Université de Bordeaux 2 - Victor-Segalen, 33000 Bordeaux, France.
authors.forename: C
authors.initials: C
authors.lastname: Gonzalez
authors.affiliation: Endocrinologie-diabétologie-nutrition, équipe ECM, CHU de Martinique, 97200 Fort-de-France, Martinique.
authors.forename: C
authors.initials: C
authors.lastname: Fagour
authors.affiliation: Nutrition-diabétologie, CHU de Bordeaux, avenue de Magellan, 33600 Pessac, France; Université de Bordeaux 2 - Victor-Segalen, 33000 Bordeaux, France; Inserm, Isped, centre Inserm U897-épidemiologie-biostatistique, 33000 Bordeaux, France.
authors.forename: E
authors.initials: E
authors.lastname: Maury
authors.affiliation: Nutrition-diabétologie, CHU de Bordeaux, avenue de Magellan, 33600 Pessac, France; Université de Bordeaux 2 - Victor-Segalen, 33000 Bordeaux, France.
authors.forename: B
authors.initials: B
authors.lastname: Cherifi
authors.affiliation: Nutrition-diabétologie, CHU de Bordeaux, avenue de Magellan, 33600 Pessac, France; Université de Bordeaux 2 - Victor-Segalen, 33000 Bordeaux, France.
authors.forename: S
authors.initials: S
authors.lastname: Salandini
authors.affiliation: Nutrition-diabétologie, CHU de Bordeaux, avenue de Magellan, 33600 Pessac, France; Université de Bordeaux 2 - Victor-Segalen, 33000 Bordeaux, France.
authors.forename: A
authors.initials: A
authors.lastname: Pierreisnard
authors.affiliation: Nutrition-diabétologie, CHU de Bordeaux, avenue de Magellan, 33600 Pessac, France; Université de Bordeaux 2 - Victor-Segalen, 33000 Bordeaux, France.
authors.forename: P
authors.initials: P
authors.lastname: Masquefa-Giraud
authors.affiliation: Nutrition-diabétologie, CHU de Bordeaux, avenue de Magellan, 33600 Pessac, France; Université de Bordeaux 2 - Victor-Segalen, 33000 Bordeaux, France.
authors.forename: H
authors.initials: H
authors.lastname: Gin
authors.affiliation: Nutrition-diabétologie, CHU de Bordeaux, avenue de Magellan, 33600 Pessac, France; Université de Bordeaux 2 - Victor-Segalen, 33000 Bordeaux, France; Inserm, Isped, centre Inserm U897-épidemiologie-biostatistique, 33000 Bordeaux, France. Electronic address: vincent.rigalleau@chu-bordeaux.fr.
authors.forename: V
authors.initials: V
authors.lastname: Rigalleau
mesh_terms: D000368:Aged; D001786:Blood Glucose / Q000187:drug effects / Q000378:metabolism; D001835:Body Weight / Q000187:drug effects; D015331:Cohort Studies; D003924:Diabetes Mellitus, Type 2 / Q000188:drug therapy* / Q000378:metabolism*; D004734:Energy Metabolism / Q000187:drug effects; D005260:Female; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans; D007328:Insulin / Q000008:administration & dosage / Q000031:analogs & derivatives*; D008297:Male; D008875:Middle Aged; D056152:Respiratory Rate / Q000187:drug effects; D012146:Rest
chemical_list: D001786:Blood Glucose; D006442:Glycated Hemoglobin; D007328:Insulin
keywords: Insulin therapy; Respiratory quotient; Resting energy expenditure; Type 2 diabetes