Obesity In Elderly Women Is Associated With Insulin Resistance Of Glucose And Protein Metabolism
Bibliographic record
Abstract
We have previously shown that normal aging is associated with insulin resistance of glucose metabolism that also extends to that of protein. Obesity creates particular metabolic changes that contribute in further decreasing insulin sensitivity of glucose metabolism. How obesity affects insulin sensitivity of protein metabolism in the elderly remains unknown. PURPOSE: To compare insulin sensitivity of whole-body glucose and protein metabolism between obese (O) and non-obese (NO) elderly women. METHODS: [13C] leucine kinetics were measured in 10 healthy NO and 8 healthy O elderly women in the postabsorptive state and during a hyperinsulinemic (40 mU · m-2 · min-1), euglycemic (5.5 mmol · L-1), isoaminoacidemic (amino acids maintained at individual baseline) clamp for 210 min. Body composition was measured using bioelectrical impedance analysis with validated equations. Volunteers followed a 7-day, isoenergetic formula-based diet before the clamp comprising 1.8 g protein · kg fat-free mass (FFM)-1 · day-1. RESULTS: Age did not differ (O: 72 ± 4 vs. NO: 70 ± 6 yrs), and body mass (77 ± 9 vs. 57 ± 7 kg), body mass index (31 ± 3 vs. 23 ± 2 kg · m-2), FFM (40 ± 3 vs. 36 ± 3 kg) and fat mass (FM) (37 ± 6 vs. 22 ± 5 kg) were significantly higher in O than NO (all P < 0.02). In the postabsorptive state, leucine rate of appearance (Ra, protein breakdown) was 12% higher (P < 0.01) and disappearance (Rd, synthesis) 10% higher (P < 0.01) in O than NO, but leucine oxidation and net balance did not differ between groups. With hyperinsulinemia, insulin sensitivity (glucose infusion rate · FFM-1/mean plateau insulin) was 56% less (P = 0.02) in O than NO, with no difference in the rate of amino acid infusion between groups. The percent change in leucine flux, Ra and Rd was not different between groups, but that of leucine oxidation was 26% higher (P = 0.02) in O than NO. FM (kg) correlated (r = 0.70, P < 0.01) with the % change in leucine oxidation. CONCLUSION: In addition to demonstrating a reduced insulin sensitivity of glucose metabolism, our results suggest that obese elderly women also have a blunted protein anabolic response to hyperinsulinemia due to increased losses through oxidation.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".