Obesity and diabetes: similar respiratory mechanical but different gas exchange defects

Abstract

Diabetes mellitus increases smooth muscle tone and causes tissue remodelling affecting elastin and collagen. Since lung is dominated by these elements, diabetes is expected to modify the airway function and respiratory tissue mechanics. Therefore, we characterized the respiratory function in patients with diabetes with and without associated obesity. Mechanically ventilated patients with normal body shapes were divided into the control non-diabetic (n=73) and diabetic (n=31) groups. The other two groups included obese patients without diabetes (n=43) or with diabetes (n=30). The mechanical properties of the respiratory system were determined by forced oscillation technique. Airway resistance (Raw), tissue damping (G), and tissue elastance (H) were assessed by forced oscillation. Capnography was applied to determine phase 3 slopes and dead space indices. The intrapulmonary shunt fraction (Qs/Qt) and the lung oxygenation index (PaO2/FiO2) were estimated from arterial and central venous blood samples. Compared with the corresponding control groups, diabetes alone increased the Raw (7.6 ± 6 cmH2O.s/l vs. 3.1 ± 1.9 cmH2O.s/l), G (11.7 ± 5.5 cmH2O/l vs. 6.5 ± 2.8 cmH2O/l), and H (31.5 ± 11.8 cmH2O/l vs. 24.2 ± 7.2 cmH2O/l, (p < 0.001 for all). Diabetes increased the capnographic phase 3 slope, whereas PaO2/FiO2 or Qs/Qt were not affected. Obesity alone caused similar detrimental changes in respiratory mechanics and alveolar heterogeneity, but these alterations also compromised gas exchange. We conclude that diabetes-induced intrinsic mechanical abnormalities are counterbalanced by hypoxic pulmonary vasoconstriction, which maintained intrapulmonary shunt fraction and oxygenation ability of the lungs.

Effect of body position on the redistribution of regional lung aeration during invasive and non-invasive ventilation of COVID-19 patients

“…This finding suggests that, in C-ARDS, regional ventilation and perfusion of the open lung regions might be more homogeneous than in non-COVID ARDS. Conversely, in terms of Bohr and Enghoff dead space, the changes are similar to those observed in non-COVID ARDS 39 and were markedly higher than those obtained for ventilated patients with healthy lungs 38,40 . A marked elevation in the difference between the Bohr and Fowler dead spaces (VD B -VD F ) is observed regardless of the body position, which suggests the presence of large lung regions that are ventilated but not perfused.…”

“…A marked elevation in the difference between the Bohr and Fowler dead spaces (VD B -VD F ) is observed regardless of the body position, which suggests the presence of large lung regions that are ventilated but not perfused. Similarly, the difference between the Enghoff and Bohr dead spaces (VD E -VD B ) is much higher than in healthy ventilated patients 38,40 , indicating the development of alveolar regions with intrapulmonary shunt. Moreover, prone positioning significantly decreased the Enghoff 's dead space VD E for intubated patients, suggesting a beneficial redistribution of lung aeration.…”

A rationally engineered specific near-infrared fluorogenic substrate of human pancreatic lipase for functional imaging and inhibitor screening

“…2 Of particular note, obesity not only leads to aesthetic and psychological issues but is also closely linked to many metabolic illnesses such as diabetes, hypertension, hyperlipidaemia, fatty liver and cardiovascular disease. [3][4][5] The therapy of obesity will therefore significantly reduce the prevalence of chronic metabolic diseases and mortality. 6 Ideally, obesity treatment mainly relies on an appropriate diet and lifestyle changes.…”

Relationship between weight-adjusted waist index and handgrip strength in adults aged 50 and older in the United States: a cross-sectional study.

“…In the United States, over 32% of adults are reported to be obese [2]. Recent studies have established connections between obesity and various health conditions, such as type II diabetes [3], hypertension [4], dyslipidemia [5], and sleep apnea syndrome [6].…”