OBJECTIVE -Alveolar microvascular function is moderately impaired in type 1 diabetes, as manifested by restriction of lung volume and diffusing capacity (DL CO ). We examined whether similar impairment develops in type 2 diabetes and defined the physiologic sources of impairment as well as the relationships to glycemia and systemic microangiopathy. RESEARCH DESIGN AND METHODS-A cross-sectional study was conducted at a university-affiliated diabetes treatment center and outpatient diabetes clinic, involving 69 nonsmoking type 2 diabetic patients without overt cardiopulmonary disease. Lung volume, pulmonary blood flow (Q ), DL CO , membrane diffusing capacity (measured from nitric oxide uptake [DL NO ]), and pulmonary capillary blood volume (V C ) were determined at rest and exercise for comparison with those in 45 healthy nonsmokers as well as with normal reference values.RESULTS -In type 2 diabetic patients, peak levels of oxygen uptake, Q and DL CO , DL NO , and V C at exercise were 10 -25% lower compared with those in control subjects. In nonobese patients (BMI Ͻ30 kg/m 2 ), reductions in DL CO , DL NO , and V C were fully explained by the lower lung volume and peak Q , but these factors did not fully explain the impairment in obese patients (BMI Ͼ30 kg/m 2 ). The slope of the increase in V C with respect to Q was reduced ϳ20% in patients regardless of BMI, consistent with impaired alveolar-capillary recruitment. Functional impairment was directly related to A1C level, retinopathy, neuropathy, and microalbuminuria in a sex-specific manner.CONCLUSIONS -Alveolar microvascular reserves are reduced in type 2 diabetes, reflecting restriction of lung volume, alveolar perfusion, and capillary recruitment. This reduction correlates with glycemic control and extrapulmonary microangiopathy and is aggravated by obesity.

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PurposeTo identify rates of postoperative radiation therapy (RT) after breast conservation surgery (BCS) in women with stage I or II invasive breast cancer treated in Puerto Rico and to examine the sociodemographic and health services characteristics associated with variations in receipt of RT.MethodsThe Puerto Rico Central Cancer Registry–Health Insurance Linkage Database was used to identify patients diagnosed with invasive breast cancer between 2008 and 2012 in Puerto Rico. Claims codes identified the type of surgery and the use of RT. Logistic regression models were used to examine the independent association between sociodemographic and clinical covariates.ResultsAmong women who received BCS as their primary definitive treatment, 64% received adjuvant RT. Significant predictors of RT after BCS included enrollment in Medicare (odds ratio [OR], 2.14; 95% CI, 1.46 to 3.13; P ≤ .01) and dual eligibility for Medicare and Medicaid (OR, 1.61; 95% CI, 1.14 to 2.27; P < .01). In addition, it was found that RT was more likely to have been received in certain geographic locations, including the Metro-North (OR, 2.20; 95% CI, 1.48 to 3.28; P < .01), North (OR, 1.78; 95% CI, 1.20 to 2.64; P < .01), West (OR, 4.04; 95% CI, 2.61 to 6.25; P < .01), and Southwest (OR, 2.79; 95% CI, 1.70 to 4.59; P < .01). Furthermore, patients with tumor size > 2.0 cm and ≤ 5.0 cm (OR, 0.61; 95% CI, 0.40 to 0.93; P = .02) and those with tumor size > 5.0 cm (OR, 0.37; 95% CI, 0.15 to 0.92; P = .03) were found to be significantly less likely to receive RT.ConclusionUnderuse of RT after BCS was identified in Puerto Rico. Patients enrolled in Medicare and those who were dually eligible for Medicaid and Medicare were more likely to receive RT after BCS compared with patients with Medicaid alone. There were geographic variations in the receipt of RT on the island.

Background We developed a simple method for simulating a rebreathing maneuver to test the accuracy of the apparatus for simultaneous measurement of lung volume, diffusing capacity of the lung for carbon monoxide (DLCO), diffusing capacity of the lung for nitric oxide (DLNO), and pulmonary blood flow (Q.c). Methods A test gas mixture containing 0.3% methane, 0.3% CO, 0.8% acetylene, 30% O2, and 40 ppm nitric oxide in balance of nitrogen was sequentially diluted with a rebreathing gas mixture containing 0.3% acetylene, 0.3% methane, and 21% O2 in balance of nitrogen in order to simulate the in vivo end-tidal disappearance of the test gas mixture. Simulation of one rebreathing maneuver consisted of at least four serial dilution steps with a performance time of < 5 min. Using this technique, we estimated functional residual capacity, Q.c, DLCO, and DLNO at various flow rates and dilution ratios (0.95 to 4.04 L, 3.54 to 6.83 L/min, 7.27 to 15.12 mL/min/mm Hg, and 6.51 to 12.00 mL/min/mm Hg, respectively) and verified simulation results against nominal values. The same apparatus also could simulate a single-breath procedure. Results Compared to nominal values, errors in measured values by rebreathing and single-breath DLCO simulation remained < 5% and 7%, respectively. Slopes of the correlations were close to 1.0 (within ± 5% and ± 6.4% in rebreathing and single-breath DLCO simulation studies, respectively). Conclusion The results demonstrate the feasibility of this simulation method for standardizing the experimental measurements obtained by rebreathing and single-breath techniques. Incorporation of these simulation steps enhances the noninvasive assessment of cardiopulmonary function.