title: In Search of the Ideal Resistance Training Program to Improve Glycemic Control and its Indication for Patients with Type 2 Diabetes Mellitus: A Systematic Review and Meta-Analysis.
abstract: BACKGROUND
  Resistance training (RT) is effective for glycemic control in type 2 diabetes mellitus (T2DM) patients. However, the characteristics of an RT program that will maximize its effect and those of patients that will especially benefit from RT are unknown.
  
  
  OBJECTIVE
  The objectives of this systematic review were to identify via a comprehensive meta-analysis the characteristics of an RT program for patients with T2DM that might increase the patients' improvement in glycemic control and the characteristics of patients that will benefit from RT.
  
  
  METHODS
  Electronic-based literature searches of MEDLINE and EMBASE entries from 1 January 1966 to 25 August 2014 were conducted to identify clinical trials examining the effect of RT on glycemic control among patients with T2DM. Study keywords were text words and thesaurus terms related to RT and T2DM.
  
  
  METHODS
  Studies were included if they (1) were clinical trials consisting of two groups with and without RT exercise intervention; (2) had an intervention period of at least 5 weeks; (3) clarified that all patients had T2DM; and (4) reported or made it possible to estimate the effect size [i.e., change in glycosylated hemoglobin (HbA1c) in the RT group minus that in the control group] and its corresponding standard error.
  
  
  METHODS
  The effect size in each study was pooled with a random-effects model. Analyses were stratified by several key characteristics of the patients and RT exercise programs; meta-regression analysis was then used to detect a difference in the effect size among strata within each factor. Linear regression analyses were added by entering each of the following profiles: patients' baseline characteristics [mean baseline age, body mass index (BMI), and HbA1c levels] and exercise characteristics (total sets per week, total sets per bout of exercise, frequency, and intensity).
  
  
  RESULTS
  There were 23 eligible studies comprising 954 patients with T2DM. The pooled effect size (95% confidence interval) was -0.34% (-0.53 to -0.16). A program with multiple sets (≥21 vs. <21) per one RT bout was associated with a large effect size (P = 0.03); however, the linear correlation between the number of sets and effect size was not significant (P = 0.56). A larger effect size was observed in studies with participants with diabetes of a relatively short duration (<6 vs. ≥6 years; P = 0.04) or a high baseline HbA1c [≥7.5% (58 mmol/mol) vs. <7.5 %; P = 0.01] while a smaller effect size was observed in studies with a particularly high mean baseline BMI value (≥32 vs. <32 kg/m(2); P = 0.03). Linear regression analyses predicted that each increment of 1% in the baseline HbA1c would enlarge the effect size by 0.036%, while each increment of 1 kg/m2 in the baseline BMI decreased it by 0.070% in the range between 22.3 and 38.8 kg/m2.
  
  
  CONCLUSIONS
  In terms of glycemic control, RT could be recommended in the early stage of T2DM, especially for patients with relatively poor glycemic control. More benefit would be elicited in less obese patients within a limited range of the BMI. A substantial amount of exercise might be required to stimulate post-exercise glucose uptake, although the dose-dependency was not specifically clarified.
authors.affiliation: Department of Hematology, Endocrinology and Metabolism, Faculty of Medicine, Niigata University, Niigata, Niigata, Japan.
authors.forename: Hajime
authors.initials: H
authors.lastname: Ishiguro
authors.affiliation: Department of Laboratory Medicine and Clinical Epidemiology, for Prevention of Noncommunicable Diseases, Graduate School of Medical and Dental Sciences, Niigata University, 1-757 Asahimachi-dori, Chuoh-ku, Niigata, 951-8510, Japan. ybbkodama@gmail.com.
authors.forename: Satoru
authors.initials: S
authors.lastname: Kodama
authors.affiliation: Department of Health and Nutrition, Faculty of Human Life Studies, University of Niigata Prefecture, Niigata, Niigata, Japan.
authors.forename: Chika
authors.initials: C
authors.lastname: Horikawa
authors.affiliation: Department of Endocrinology and Metabolism, Institute of Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan.
authors.forename: Kazuya
authors.initials: K
authors.lastname: Fujihara
authors.affiliation: Faculty of Human Welfare, Child Studies, Seigakuin University, Saitama, Japan.
authors.forename: Ayumi Sugawara
authors.initials: AS
authors.lastname: Hirose
authors.affiliation: Department of Hematology, Endocrinology and Metabolism, Faculty of Medicine, Niigata University, Niigata, Niigata, Japan.
authors.forename: Reiko
authors.initials: R
authors.lastname: Hirasawa
authors.affiliation: Department of Faculty of Health and Nutrition, Yamanashi Gakuin University, Kofu, Yamanashi, Japan.
authors.forename: Yoko
authors.initials: Y
authors.lastname: Yachi
authors.affiliation: Department of Hematology, Endocrinology and Metabolism, Faculty of Medicine, Niigata University, Niigata, Niigata, Japan.
authors.forename: Nobumasa
authors.initials: N
authors.lastname: Ohara
authors.affiliation: Department of Endocrinology and Metabolism, Institute of Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Shimano
authors.affiliation: Department of Hematology, Endocrinology and Metabolism, Faculty of Medicine, Niigata University, Niigata, Niigata, Japan.
authors.forename: Osamu
authors.initials: O
authors.lastname: Hanyu
authors.affiliation: Department of Hematology, Endocrinology and Metabolism, Faculty of Medicine, Niigata University, Niigata, Niigata, Japan.
authors.forename: Hirohito
authors.initials: H
authors.lastname: Sone
mesh_terms: D001786:Blood Glucose / Q000378:metabolism*; D015992:Body Mass Index; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000628:therapy*; D006442:Glycated Hemoglobin / Q000032:analysis*; D006801:Humans; D055070:Resistance Training / Q000379:methods*
chemical_list: D001786:Blood Glucose; D006442:Glycated Hemoglobin