Is Oxygen Consumption and Oxygen Delivery During Leg Exercise Compromised in Type II Diabetes?
Bibliographic record
Abstract
Evidence is emerging that muscle oxygen delivery and possibly also muscle oxygen consumption responses may be blunted in type II diabetes (T2D). PURPOSE: To determine whether dynamic and steady state adjustments in VO2 to exercise are impaired in T2D and whether this is accompanied by slower and/or reduced muscle blood flow responses. METHODS: Four males with T2D (54.8 ± 4.1 yrs) and six healthy, activity matched male controls (CON) (44.3 ± 2.7 yrs) performed 3 protocols of supine, two-leg knee extension/flexion exercise i) incremental exercise to exhaustion, ii) rest to low intensity step (LO7.5kg; 7.5 kg resistance), iii) rest to moderate intensity step (VT90%; 90% of ventilatory threshold) on separate days. Femoral artery blood flow (FABF; Doppler and Echo ultrasound), and VO2 (Metabolic Cart) were measured continuously at rest and throughout exercise. RESULTS: Means are ±SE. Fasting plasma glucose and HbA1c% were elevated in T2D vs. CON (8.2 ± 1.1 vs. 5.6 ± 0.3 mmol/L, P=0.035; 7.4 ± 0.9 vs. 5.3 ± 0.1 %, P=0.023). Neither peak VO2 nor peak work rate were different in T2D vs. CON (1711.1 ± 170.8 vs. 1852.0 ± 162.0 ml/min, P= 0.579; 16.4 ± 1.0 vs. 18.7 ± 1.4 kg) indicating matched fitness. For rest to exercise steps: the change from baseline (D) for VO2 was not different between groups at any time point for LO7.5kg (P=0.351), but DFABF in the rapid initial phase I response was blunted in T2D (FABF for two legs; 2120.4 ± 218.4 ml/min vs. 3435.6 ± 275.0, P= 0.018). Mean response time (MRT; time required to achieve 63% of the total response magnitude) tended to be slower (LO7.5kg; 23.1 ± 4.2s vs. 14.3 ± 1.7s; VT90%: 40.0 ± 7.5s vs.26.2 ± 3.5s; P=0.095). For incremental exercise: DVO2 was not different between groups at 7.5, 10 and 13 kg (P=0.264). DFABF in T2D was not statistically significantly reduced (P=0.098), whereas absolute FABF was lower at rest 617.0 ± 22.1 vs.959.8 ± 111.3 ml/min, P=0.04) and 10 and 13 kg workloads (P=0.035 and 0.007 respectively). Movement artifact prevented FABF measures above these work rates. CONCLUSIONS: T2D is characterized by impaired vasodilatory mechanisms involved in the rapid initial response to exercise, and may impair blood flow adjustments to incremental exercise. However, these effects do not impair increases in VO2, indicating increased oxygen extraction compensates in this exercise model.
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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 | 0.001 | 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 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 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".