Relationship between pulmonary function and albuminuria in type 2 diabetic patients with preserved renal function

Associations between spirometric impairments and microvascular complications in type 2 diabetes: a cross-sectional study

OBJECTIVE

Evidence shows that the conventional cardiometabolic risk factors do not fully explain the burden of microvascular complications in type 2 diabetes (T2D). One potential factor is the impact of pulmonary dysfunction on systemic microvascular injury. We assessed the associations between spirometric impairments and systemic microvascular complications in T2D.

DESIGN

Cross-sectional study.

SETTING

National Diabetes Management and Research Centre in Ghana.

PARTICIPANTS

The study included 464 Ghanaians aged ≥35 years with established diagnosis of T2D without primary myocardial disease or previous/current heart failure. Participants were excluded if they had primary lung disease including asthma or chronic obstructive pulmonary disease.

PRIMARY AND SECONDARY OUTCOME MEASURES

The associations of spirometric measures (forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC) and FEV1/FVC ratio) with microvascular complications (nephropathy (albumin-creatinine ratio ≥3 mg/g), neuropathy (vibration perception threshold ≥25 V and/or Diabetic Neuropathy Symptom score >1) and retinopathy (based on retinal photography)) were assessed using multivariable logistic regression models with adjustments for age, sex, diabetes duration, glycated haemoglobin concentration, suboptimal blood pressure control, smoking pack years and body mass index.

RESULTS

In age and sex-adjusted models, lower Z-score FEV1 was associated with higher odds of nephropathy (OR 1.55, 95% CI 1.19-2.02, p=0.001) and neuropathy (1.27 (1.01-1.65), 0.038) but not retinopathy (1.22 (0.87-1.70), 0.246). Similar observations were made for the associations of lower Z-score FVC with nephropathy (1.54 (1.19-2.01), 0.001), neuropathy (1.25 (1.01-1.54), 0.037) and retinopathy (1.19 (0.85-1.68), 0.318). In the fully adjusted model, the associations remained significant for only lower Z-score FEV1 with nephropathy (1.43 (1.09-1.87), 0.011) and neuropathy (1.34 (1.04-1.73), 0.024) and for lower Z-score FVC with nephropathy (1.45 (1.11-1.91), 0.007) and neuropathy (1.32 (1.03-1.69), 0.029). Lower Z-score FEV1/FVC ratio was not significantly associated with microvascular complications in age and sex and fully adjusted models.

CONCLUSION

Our study shows positive but varying strengths of associations between pulmonary dysfunction and microvascular complications in different circulations. Future studies could explore the mechanisms linking pulmonary dysfunction to microvascular complications in T2D.

Impact of Diabetic Nephropathy on Pulmonary Function and Clinical Outcomes

Objective

The main objective is to study the effect of diabetic nephropathy on pulmonary function and clinical outcomes.

Methods

The method is to retrospectively analyze patients with diabetic nephropathy (DN) in our hospital from April 2018 to March 2022 as study subjects. The differences in baseline data, serum indicators, renal function indicators, and pulmonary function of patients at different clinical stages were analyzed and then explored. Finally, logistic regression was used to analyze the risk factors affecting patients' clinical outcomes and to evaluate the diagnostic effects.

Results

Baseline information (age, disease duration, BMI, and systolic and diastolic blood pressure), serum indicators (HbA1c, FBG, 2hPG, TG, TC, and LDLC), renal function indicators (CysC, BUN, and Scr), and pulmonary function (TLC, VC, FEV1, FEV1/FVC, MVV, MEF25, MEF50 MEF75, DLCO, and DLCO/VA) were significantly different (P < 0.01); multiple logistic regression analysis showed that SBP, HbA1c, FBG, 2hPG, BUN, Scr, TLC, VC, FEV1/FVC, MVV, DLCO, and DLCO/VA were all key factors in the development of clinical outcomes in DN (P < 0.05). ROC analysis showed that all of these important factors had an AUC greater than 0.75 for the diagnosis of DN with high sensitivity and specificity.

Conclusion

Serum and renal function indices of DN patients gradually increased with stage, accompanied by a decrease in pulmonary ventilation, and diffusion function; SBP, HbA1c, FBG, 2hPG, BUN, Scr, TLC, VC, FEV1/FVC, MVV, DLCO, and DLCO/VA were all key factors affecting the clinical outcome of DN; controlling blood glucose, lipids, improving pulmonary ventilation, and diffusion function can better prevent the occurrence and worsening of DN.