Lifestyle Intervention and Adipokine Levels in Subjects at High Risk for Type 2 Diabetes

Abstract

OBJECTIVE -We investigated whether circulating adipokine concentrations can be altered by lifestyle intervention according to general recommendations in subjects at risk for diabetes as well as the potential of leptin, adiponectin, and resistin as biomarkers for lifestyle-induced improvements in glucose metabolism and insulin resistance. RESEARCH DESIGN AND METHODS -In the Study on Lifestyle intervention andImpaired glucose tolerance Maastricht, 147 men and women with impaired glucose tolerance (IGT) were randomized to either a combined diet-and-exercise intervention or a control program. At baseline and after 1 year, an oral glucose tolerance test, an exercise test, and anthropometric measurements were performed. After 1 year, complete data of 103 subjects (50 intervention and 53 control subjects) were obtained.RESULTS -Lifestyle intervention reduced plasma leptin concentrations (Ϫ14.2%) in IGT subjects but did not alter plasma adiponectin (Ϫ0.3%) or resistin (Ϫ6.5%) concentrations despite marked improvements in glucose tolerance and insulin resistance.CONCLUSIONS -Changes in leptin concentration were related to improvements in insulin sensitivity independent of changes in body composition. Diabetes Care 30:3125-3127, 2007A dipokines produced by adipose tissue, such as adiponectin, resistin, and leptin, may link obesity to insulin resistance, impaired glucose metabolism, and type 2 diabetes (1). Crosssectional evidence for an association between insulin resistance and inflammation profile is ample (2). Nevertheless, the reported effects of lifestyle intervention on adipokines are limited and inconclusive (3,4). The first aim of the present study was to investigate whether circulating adipokine concentrations can be altered by lifestyle intervention according to general recommendations in subjects at risk for diabetes. Second, we investigated the potential of leptin, adiponectin, and resistin as biomarkers for lifestyleinduced improvements in glucose metabolism and insulin resistance. We addressed these aims in the Study on Lifestyle intervention and Impaired glucose tolerance Maastricht (SLIM).RESEARCH DESIGN AND METHODS -Study design, inclusion and exclusion criteria, and the diet and exercise program of SLIM, an ongoing, randomized, controlled trial, have previously been described in detail (5,6). Each year, anthropometry, body fat percentage (7), physical fitness (VO 2max ), and plasma metabolites during fasting and 2 h after a 75-g oral glucose load are determined. The study protocol was approved by the local medical ethical committee of the Maastricht University. All subjects gave written informed consent.Fasting plasma adiponectin (full length and globular, coefficient of variation [CV] 6.2%), resistin (homodimeric, CV 4.0%), and leptin (CV 5.8%) were simultaneously analyzed with enzymelinked immunosorbent assays (Biovendor, Heidelberg, Germany). Of the 147 subjects enrolled, 131 completed the first year. For regression analysis, 28 subjects were excluded because of missing values for dietary intake (n ϭ ...

Effect of diet on adiponectin levels in blood

“…In 27 (51.9%) studies, evaluation of the intervention effect on adiponectin blood levels was the primary outcome, while in others, determination of adiponectin levels was a secondary outcome 21–23,26–29,31,36,38–40,43,46,47,53–55,60,62,65,68,69,71 . Most studies (90.4%) analyzed only the total adiponectin form, while the measurement of at least one of the adiponectin multimeric forms was performed in five studies 26–28,42,71 .…”

“…Two studies did not report the gender of participants, 42,57 and other studies ( n = 28) included both female and male participants. Most studies (76.9%) included only overweight participants 20–24,26–38,43,45–48,50–52,55–59,62–71 …”

“…In 10 (19.2%) studies, the aim was to evaluate the role of diet combined with exercise in adiponectin modulation 62–71 . The details of these clinical trials are summarized in Table 3 in chronological order of publication.…”

Lifestyle intervention for prevention of diabetes: determinants of success for future implementation

“…For example, baseline levels of adiponectin, an adipose‐derived adipokine, seemed to be a strong predictor of incident diabetes in the DPP 46 . Considerable weight loss seems to restore high adiponectin levels, 47,48 but lifestyle interventions according to general guidelines do not seem to have a relevant effect on adiponectin in diabetic patients, 49 IGT subjects, 50 or obese subjects 51 . Leptin, another adipokine, seems to also be related to improvements in insulin sensitivity, independent of changes in body composition 50 …”

Prevention of type 2 diabetes with the Chinese herbal medicine Tianqi capsule: a systematic review and meta-analysis

“…Firstly, we had few studies to examine and limited statistical power to detect the differences across studies. Secondly, average follow-up for included trials was 1 year, which was similar to the SLIM study [30], but this is insufficient to assess long-term quality of life, The incidence of diabetes was analyzed according to different criteria based on treatment duration, sample size, use of placebo, and publication language. RR is risk ratio, CI is confidence interval.…”