Association between lung capacity and abnormal glucose metabolism: findings from China and Australia

Association of lung function and blood glucose level: a 10-year study in China

BACKGROUND

At present, chronic respiratory diseases are a major burden in terms of morbidity and mortality and are of increasing public health concern in China. Meanwhile, the prevalence of diabetes has increased by more than 10 times over the last 40 years. While a few studies have investigated the association between chronic respiratory diseases and diabetes mellitus, the association is not clear. This study aimed to explore this association and provide evidence.

METHODS

In this single-center study, we enrolled participants aged ≥ 20 years undergoing at least two regular health check-ups from 2009 to 2019 at MJ Healthcare Center in Beijing. Each health check-up included physical examination, biochemical tests, a pulmonary function test, a questionnaire. A total of 11,107 adults were included, and cross-sectional and longitudinal analyses were performed.

RESULTS

We found that both prediabetic and diabetic adults had lower lung function than the normal population at baseline, indicating that lung function decline may start from prediabetic status. Quantitatively, with 1-mmol/L increase in fasting plasma glucose level, the forced vital capacity (FVC), forced expiratory volume in 1 s (FEV₁), FVC% and FEV₁% lowered by 25 ml, 13 ml, 0.71-1.03%, and 0.46-0.72%, respectively. However, no significant difference was found in the rates for the lung function decline among different baseline diabetes statuses.

CONCLUSION

People with higher blood glucose level had more severe lung function decline, with decline starting from prediabetic status, but no significant difference was noted in the rate of lung function decline based on different baseline diabetic statuses.

Physical activity and fasting glucose in adults with abnormal glucose metabolism: Findings from two independent cross-sectional studies in China

BACKGROUND

Relationship between physical activity and fasting glucose in people with abnormal glucose metabolism is not well-known. This study was to investigate dose-response association between physical activity (PAT) and fasting glucose from two independent surveys among Chinese adults with abnormal glucose metabolism.

METHODS

9419 adults with abnormal glucose metabolism from two independent surveys among Chinese adults were analyzed. Demographics, level of fasting glucose and PAT (in Met Score) were measured. Dose-response relationship between fasting glucose and PAT was assessed by natural cubic spline model. Certain threshold point was identified, and linear regression models were then used within each threshold interval to assess the liner relationship functions. Models were adjusted for confounding factors and were stratified in subgroup analyses by the main population characteristics including survey site, gender and age-group.

RESULTS

Overall the relationship between PAT and fasting glucose was not in a linear association (Linearity test: p < 0.0001). Level of fasting glucose was not associated with amount of PAT until a threshold point (square-rooted Met Score 66.6 (original Met score: 4436 MET-minutes per week), 95% confidence intervals (65.2-69.3 (4,251-4,802 MET-minutes per week)). After this threshold, an inverse association was observed: each increase of every standard deviation of square-rooted Met Score 29.8 (888 MET-minutes per week) was associated with a 0.25 mmol/L decrease in fasting glucose, with adjustment for confounding factors. The patterns of relationship were tested to be consistent in subgroup analyses by survey site, gender and age group.

CONCLUSIONS

Our study indicated that among adults with abnormal glucose metabolism the level of fasting glucose was only inversely associated with square-rooted Met Score beyond a certain square-rooted Met Score amount.

Eligibility of the Systolic Blood Pressure Intervention Trial (SPRINT) to the Chinese Adults

Objective

To explore the proportion and characteristic of Chinese adults meeting The Systolic Blood Pressure Intervention Trial (SPRINT) eligibility criteria and assess its generalizability.

Method

Our study was based on a cross-sectional, population-based survey with a sample of 26,093 participants aged over 20 years. The SPRINT eligibility criteria were age ≥ 50 years, elevated SBP of 130 to 180 mmHg depending on the number of antihypertensive medication classes being taken, and increased cardiovascular disease (CVD) but without diabetes, history of stroke and estimated glomerular filtration rate < 20 ml/min/1.73 m², or receiving dialysis.

Results

Overall, we estimated that 4,036 (15.5%) participants would meet the SPRINT eligibility criteria. They were generally older, likely to be female, lower educational level, tended to be more overweight, and had higher Framingham risk score compared with overall population or subjects aged ≥ 50 years. Of participants eligible for SPRINT, most (56.2%) of them were not treated for hypertension, and 542 (13.4%) were not previously considered to have hypertension or need for antihypertension therapy. Among the 11,637 adults with hypertension, 3,494 (30.0%) would potentially benefit from treatment intensification. The most common antihypertensive medication class being taken was diuretic agents.

Conclusion

A substantial percentage of Chinese subjects meet the SPRINT eligibility criteria. Further studies are needed to assess the cost-effectiveness from treatment intensification in Chinese setting.

Dose-response association between physical activity and clustering of modifiable cardiovascular risk factors among 26,093 Chinese adults

BACKGROUND

There is uncertain evidence in the dose-response association between overall physical activity levels and clustering of cardiovascular diseases modifiable risk factors (CVDMRF) in Chinese adults. This study examined the hypothesis whether inverse dose-response association between overall physical activity levels and clustering of CVDMRF in Chinese adults exist.

METHODS

Twenty-six thousand ninety-three Chinese adult participants were recruited by two independent surveys in Nanjing and Hefei during 2011 to 2013, from random selected households provided smoking, glucose, lipids, anthropometric, and blood pressure measurements. Logistic regression model was applied to examine the dose-response association between overall physical activity (measured by metabolic equivalent task (MET)- minutes per week) and having ≥1, ≥2, and ≥ 3 CVDMRF (dyslipidemia, hypertension, diabetes, cigarette smoking, and overweight).

RESULTS

An inverse linear dose-response relationship between physical activity and clustering of CVDMRF was identified, as increased physical activity levels are associated with lower odds of having clustering of CVDMRF. The adjusted odds ratio (95% confidence interval) of having ≥1, ≥2, and ≥ 3 CVRF for moderate physical activity group and high physical activity group was 0.88 (0.79 to 0.98) and 0.88 (0.79 to 0.99), 0.85 (0.78 to 0.92) and 0.85 (0.78 to 0.92), 0.84 (0.76 to 0.91) and 0.81 (0.74 to 0.89), respectively, with low physical activity as reference group.

CONCLUSIONS

Among Chinese adults, physical activity level inversely associates with clustering of CVDMRF, especially in those aged 35-54 years. Health promotion including improve physical activity should be advocated. The potential role of physical activity in the clustering of CVDMRF warrants further validation.

Walking, But Not Other Physical Activity at a Higher Intensity, Is Associated With Improved Kidney Function: A Cross-Sectional Health Survey of General Adult Population

BACKGROUND

Chronic kidney disease is common and brings significant health burden. The purpose of this study was to investigate the relationship between physical activity and kidney function.

METHODS

This was a cross-sectional study set in the Nanjing Community Cardiovascular Risk Survey, using random cluster sampling. Questionnaires were completed, wherever possible, through face-to-face interviews. Data on age, sex, body mass index, weekly physical activity, and kidney function were collected. Physical activity was measured by the metabolic equivalent of task-minutes per week and grouped into "walking," "moderate," and "vigorous" according to intensity. Kidney function was measured by the estimated glomerular filtration rate (eGFR, in mL/min/1.73 m²). Regression modeling was used to investigate the proposed relationship with adjustment for other confounding factors.

RESULTS

A total of 5824 participants were included, with an average age of 52; 44% were male. The eGFR in average was 76 mL/min/1.73 m², with 19% ≥ 90, 67% between 60 and 89, and 14% < 60. In average, the total physical activity during a week was 3644 MET-minutes per week. Moderate activity contributed 64% of the total activity, followed by walking (23%) and vigorous activity (13%). Overall, the total activity was weakly associated with eGFR (P = .039). However, in stratified analysis, only walking-related activity was associated with eGFR (P < .0001) after confounding adjustment.

CONCLUSIONS

Walking is associated with improved kidney function.

Potential health impact and cost-effectiveness of drug therapy for prehypertension

BACKGROUND

Studies have reported that pharmacologic interventions with candesartan or ramipril could reduce the risk of hypertension among prehypertensive subjects free of clinical cardiovascular disease (CVD), however, the cost-effectiveness and long-term cardiovascular risk of drug treatment among these population is unclear.

METHOD

A Markov state-transition model was developed to simulate a hypothetical cohort of Chinese adults with high-range prehypertension (130-139/85-89mmHg) but without CVD. Data on the incidence of CVD and hypertension was obtained from corresponding risk equations. Utility and disease-related costs were obtained from published literatures. Robustness and uncertainty was evaluated using deterministic and probabilistic sensitivity analyses.

RESULTS

Compared with placebo, drug treatment resulted in delaying the development of hypertension by nearly 12years and reducing the absolute incidence of hypertension by 32.01% over lifetime. The cumulative incidence of coronary heart disease, stroke and heart failure were reduced and survival was improved from 28.46 to 28.80years. The average incremental cost effectiveness ratio for drug treatment was $12,994 per quality-adjusted life-year and the value was mostly sensitive to the effect size of treatment and age starting treatment. At a willingness-to-pay threshold of >3×China gross domestic product per capita in 2014, there was a 30.48% chance that drug treatment would remain cost-effective and a low chance of being cost-effective if relative risk of treatment on hypertension was larger than 0.64.

CONCLUSION

Drug treatment for prehypertension may help stem the current epidemic of hypertension among Chinese adults free of CVD, which may in turn reduce CVD complications and potentially be cost effective.

Association between pulmonary function and renal function: findings from China and Australia

Background

The relationship between obstructive lung function and impaired renal function is unclear. This study investigated the dose-response relationship between obstructive lung function and impaired renal function.

Methods

Two independent cross-sectional studies with representative sampling were applied. 1454 adults from rural Victoria, Australia (1298 with normal renal function, 156 with impaired renal function) and 5824 adults from Nanjing, China (4313 with normal renal function, 1511 with impaired renal function). Pulmonary function measurements included forced expiratory volume in one second (FEV1) and forced vital capacity (FVC). Estimated glomerular filtration rate (eGFR), and impaired renal function marked by eGFR <60 mL/min/1.73m² were used as outcome.

Results

eGFR increased linearly with FEV1 in Chinese participants and with FVC in Australians. A non-linear relationship with peaked eGFR was found for FEV1 at 2.65 L among Australians and for FVC at 2.78 L among Chinese participants, respectively. A non-linear relationship with peaked eGFR was found for the predicted percentage value of forced expiratory volume in 1 s (PFEV1) at 81–82% and for the predicted percentage value of forced vital capacity (PFVC) at 83–84% among both Chinese and Australian participants, respectively.

The non-linear dose-response relationships between lung capacity measurements (both for FEV1 and FVC) and risk of impaired renal function were consistently identified in both Chinese and Australian participants. An increased risk of impaired renal function was found below 3.05 L both for FEV1 and FVC, respectively. The non-linear relationship between PFEV and PVC and the risk of impaired renal function were consistently identified in both Chinese and Australian participants. An increased risk of impaired renal function was found below 76–77% for PFEV1 and 79–80% for PFVC, respectively.

Conclusions

In both Australian and Chinese populations, the risk of impaired renal function increased both with FEV1 and FVC below 3.05 L, with PFEV1 below 76–77% or with PFVC below 79–80%, respectively. Obstructive lung function was associated with increased risk of reduced renal function. The screen for impaired renal function in patients with obstructive lung disease might be useful to ensure there was no impaired renal function before the commencement of potentially nephrotoxic medication where indicated (eg diuretics).

Electronic supplementary material

The online version of this article (doi:10.1186/s12882-017-0565-y) contains supplementary material, which is available to authorized users.