Limits...
Weight Loss Programs May Have Beneficial or Adverse Effects on Fat Mass and Insulin Sensitivity in Overweight and Obese Black Women.

Leon B, Miller BV, Zalos G, Courville AB, Sumner AE, Powell-Wiley TM, Walter MF, Waclawiw MA, Cannon RO - J Racial Ethn Health Disparities (2014)

Bottom Line: Weight loss interventions have produced little change in insulin sensitivity in black women, but mean data may obscure metabolic benefit to some and adverse effects for others.Baseline SI (range 0.74 to 7.58 l/mU(-1)•min(-1)) was inversely associated with fat mass (r = -0.516, p < 0.001), independent of age.Additional support for participants who fail to achieve fat mass loss early in an intervention may be required for success.

View Article: PubMed Central - PubMed

Affiliation: Cardiovascular and Pulmonary Branch, National Heart, Lung, and Blood Institute, Building 10-CRC Room 5-3330, 10 Center Drive, Bethesda, MD 20892 USA.

ABSTRACT

Objective: Weight loss interventions have produced little change in insulin sensitivity in black women, but mean data may obscure metabolic benefit to some and adverse effects for others. Accordingly, we analyzed insulin sensitivity relative to fat mass change following a weight loss program.

Design and methods: Fifty-four black women (BMI range 25.9 to 54.7 kg/m(2)) completed the 6-month program that included nutrition information and worksite exercise facilities. Fat mass was measured by dual-energy X-ray absorptiometry, and insulin sensitivity index (SI) was calculated from an insulin-modified intravenous glucose tolerance test using the minimal model.

Results: Baseline SI (range 0.74 to 7.58 l/mU(-1)•min(-1)) was inversely associated with fat mass (r = -0.516, p < 0.001), independent of age. On average, subjects lost fat mass (baseline 40.8 ± 12.4 to 39.4 ± 12.6 kg [mean ± SD], P < 0.01), but 17 women (32 %) actually gained fat mass. SI for the group was unchanged (baseline 3.3 ± 1.7 to 3.2 ± 1.6, P = 0.67). However, the tertile with greatest fat mass loss (-3.6 kg, range -10.7 to -1.7 kg) improved insulin sensitivity (SI +0.3 ± 1.2), whereas the tertile with net fat mass gain (+0.9 kg, range -0.1 to +3.8 kg) had reduced insulin sensitivity (SI -0.7 ± 1.3) from baseline values (P < 0.05 by ANOVA).

Conclusions: Black women in a weight loss program who lose fat mass may have improved insulin sensitivity, but fat mass gain with diminished sensitivity is common. Additional support for participants who fail to achieve fat mass loss early in an intervention may be required for success.

No MeSH data available.


Related in: MedlinePlus

Flow chart of participant participation
© Copyright Policy - OpenAccess
Related In: Results  -  Collection


getmorefigures.php?uid=PMC4125812&req=5

Fig1: Flow chart of participant participation

Mentions: One hundred forty-one black women were assessed for eligibility in this protocol, and 114 were enrolled for participation (Fig. 1). Of the 114 participants who underwent baseline testing, 28 women were excluded from analysis due to failed baseline or follow-up FSIGT. Reasons for failed FSIGT’s included hemolyzed samples (n = 21), inability to place intravenous lines in antecubital veins of both arms (n = 4), improper testing technique (n = 2), and poor data fit for predicted glucose disposal (n = 1). In addition, 32 women withdrew from the study prior to completing 6 months participation. Thus, 54 subjects underwent testing for fat mass and insulin sensitivity at baseline and at 6 months. To evaluate whether the characteristics of these 54 subjects differed from the remaining subjects who either had incomplete data or dropped out of the study (Fig. 1), we compared all baseline variables. The two groups did not differ in age or baseline BMI, total fat mass, % truncal fat mass, insulin, glucose, or SI (all P > 0.1). Those that dropped out or with incomplete data, however, had significantly lower baseline VO2 peak than those who completed the study (20.7 ± 4.4 vs. 22.8 ± 4.9 mL O2/kg/min, P = 0.019).Fig. 1


Weight Loss Programs May Have Beneficial or Adverse Effects on Fat Mass and Insulin Sensitivity in Overweight and Obese Black Women.

Leon B, Miller BV, Zalos G, Courville AB, Sumner AE, Powell-Wiley TM, Walter MF, Waclawiw MA, Cannon RO - J Racial Ethn Health Disparities (2014)

Flow chart of participant participation
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4125812&req=5

Fig1: Flow chart of participant participation
Mentions: One hundred forty-one black women were assessed for eligibility in this protocol, and 114 were enrolled for participation (Fig. 1). Of the 114 participants who underwent baseline testing, 28 women were excluded from analysis due to failed baseline or follow-up FSIGT. Reasons for failed FSIGT’s included hemolyzed samples (n = 21), inability to place intravenous lines in antecubital veins of both arms (n = 4), improper testing technique (n = 2), and poor data fit for predicted glucose disposal (n = 1). In addition, 32 women withdrew from the study prior to completing 6 months participation. Thus, 54 subjects underwent testing for fat mass and insulin sensitivity at baseline and at 6 months. To evaluate whether the characteristics of these 54 subjects differed from the remaining subjects who either had incomplete data or dropped out of the study (Fig. 1), we compared all baseline variables. The two groups did not differ in age or baseline BMI, total fat mass, % truncal fat mass, insulin, glucose, or SI (all P > 0.1). Those that dropped out or with incomplete data, however, had significantly lower baseline VO2 peak than those who completed the study (20.7 ± 4.4 vs. 22.8 ± 4.9 mL O2/kg/min, P = 0.019).Fig. 1

Bottom Line: Weight loss interventions have produced little change in insulin sensitivity in black women, but mean data may obscure metabolic benefit to some and adverse effects for others.Baseline SI (range 0.74 to 7.58 l/mU(-1)•min(-1)) was inversely associated with fat mass (r = -0.516, p < 0.001), independent of age.Additional support for participants who fail to achieve fat mass loss early in an intervention may be required for success.

View Article: PubMed Central - PubMed

Affiliation: Cardiovascular and Pulmonary Branch, National Heart, Lung, and Blood Institute, Building 10-CRC Room 5-3330, 10 Center Drive, Bethesda, MD 20892 USA.

ABSTRACT

Objective: Weight loss interventions have produced little change in insulin sensitivity in black women, but mean data may obscure metabolic benefit to some and adverse effects for others. Accordingly, we analyzed insulin sensitivity relative to fat mass change following a weight loss program.

Design and methods: Fifty-four black women (BMI range 25.9 to 54.7 kg/m(2)) completed the 6-month program that included nutrition information and worksite exercise facilities. Fat mass was measured by dual-energy X-ray absorptiometry, and insulin sensitivity index (SI) was calculated from an insulin-modified intravenous glucose tolerance test using the minimal model.

Results: Baseline SI (range 0.74 to 7.58 l/mU(-1)•min(-1)) was inversely associated with fat mass (r = -0.516, p < 0.001), independent of age. On average, subjects lost fat mass (baseline 40.8 ± 12.4 to 39.4 ± 12.6 kg [mean ± SD], P < 0.01), but 17 women (32 %) actually gained fat mass. SI for the group was unchanged (baseline 3.3 ± 1.7 to 3.2 ± 1.6, P = 0.67). However, the tertile with greatest fat mass loss (-3.6 kg, range -10.7 to -1.7 kg) improved insulin sensitivity (SI +0.3 ± 1.2), whereas the tertile with net fat mass gain (+0.9 kg, range -0.1 to +3.8 kg) had reduced insulin sensitivity (SI -0.7 ± 1.3) from baseline values (P < 0.05 by ANOVA).

Conclusions: Black women in a weight loss program who lose fat mass may have improved insulin sensitivity, but fat mass gain with diminished sensitivity is common. Additional support for participants who fail to achieve fat mass loss early in an intervention may be required for success.

No MeSH data available.


Related in: MedlinePlus