Chronic kidney disease, atherosclerosis, and cognitive and physical function in the geriatric group of the National Health and Nutrition Survey 1999–2002

Chronic kidney disease and functional impairment in a longitudinal study of older adults in China

OBJECTIVES

To examine the associations of chronic kidney disease (CKD) with dynamic functional impairment among older Chinese adults.

DESIGN

This was a prospective longitudinal study.

SETTING

Data were derived from the Chinese Longitudinal Healthy Longevity Study.

PARTICIPANTS

All adults aged ≥60 years were potentially eligible. This study included 2970 participants.

PRIMARY OUTCOME MEASURES

CKD was defined as an estimated glomerular filtration rate <60 mL/min/1.73 m2. Functional performances included instrumental activities of daily living (IADL) and basic activities of daily living (BADL), which were measured using six daily activities, including eating, dressing, transferring, using the toilet, bathing and continence, and eight daily activities, including visiting neighbours, shopping, cooking, washing clothes, walking 1 km, lifting 5 kg, crouching and standing up three times and taking public transportation, respectively.

RESULTS

This study included 2970 participants, including 988 (33.60%) participants with CKD. Participants with CKD had higher IADL scores than those without CKD (β=0.895, 95% CI: 0.761 to 1.029). Furthermore, there was a significant linear trend in the association of CKD severity with the IADL score (p<0.001). Similarly, CKD was significantly associated with higher BADL scores (β=0.067, 95% CI: 0.017 to 0.118). However, only participants with moderate and advanced CKD had a higher BADL score (β=0.088 and 0.152, 95% CI: 0.006 to 0.171 and 0.019 to 0.286, respectively).

CONCLUSIONS

CKD was associated with worse functional impairment. Furthermore, there was a significant linear trend in the association of the severity of CKD with the IADL score. However, only participants with moderate and advanced CKD had higher BADL scores.

The associations between renal disease severity and exposure to organophosphate flame retardants in patients with chronic kidney disease

Organophosphate flame retardants (OPFRs) are emerging and widespread environmental pollutants with potential health hazards, including nephrotoxicity. However, the exposure patterns and nephrotoxic potential of OPFRs are yet to be investigated in patients with chronic kidney disease (CKD). We conducted a cross-sectional study involving 166 patients with CKD stratified by estimated glomerular filtration rate (eGFR) and severity of proteinuria. The urinary concentrations of 10 OPFR compounds were measured to evaluate the exposure patterns. Clinical and urinary OPFR profiles were compared among subgroups to identify whether the OPFR compounds were independently correlated with eGFR and proteinuria. Additionally, lifestyle factors were compared among subgroups stratified by median concentrations of urinary OPFR compounds associated with renal disease severity. This study revealed universal exposure to OPFRs in the CKD population, with an overall urinary detection rate of 98.80 %. Furthermore, after adjusting for covariates, the urinary concentration of bis(2-chloroethyl) phosphate (BCEP) was identified as an independent predictor of lower eGFR (low vs high eGFR, odds ratio (OR) (95 % confidence interval (CI)), 1.761 (1.032-3.005) per log μg/g creatinine, p = 0.038), and the urinary concentration of bis(2-butoxyethyl) phosphate (BBOEP) was independently correlated with overt proteinuria in CKD patients (with vs without overt proteinuria, OR (95 % CI), 1.813 (1.065-3.086) per log μg/g creatinine, p = 0.028). Moreover, frequent seafood consumption was negatively correlated with urinary BCEP concentration (high vs low BCEP, OR (95 % CI), 0.455 (0.228-0.908), p = 0.025), and age was inversely associated with urinary BBOEP concentration (high vs low BBOEP, OR (95 % CI), 0.968 (0.937-0.999) per year, p = 0.048). In conclusion, our investigation highlights the extensive exposure to OPFRs and the independent association between renal disease severity and urinary BCEP/BBOEP concentrations in the CKD population, indicating the nephrotoxic potential of these pollutants.

The assessment of cognitive function in older adult patients with chronic kidney disease: an integrative review

INTRODUCTION

Chronic kidney disease (CKD) is a common chronic condition in older adults that is associated with cognitive decline. However, the exact prevalence of cognitive impairment in older adults with CKD is unclear likely due to the variety of methods utilized to assess cognitive function. The purpose of this integrative review is to determine how cognitive function is most frequently assessed in older adult patients with CKD.

METHODS

Five electronic databases were searched to explore relevant literature related to cognitive function assessment in older adult patients with CKD. Inclusion and exclusion criteria were created to focus the search to the assessment of cognitive function with standardized cognitive tests in older adults with CKD, not on renal replacement therapy.

RESULTS

Through the search methods, 36 articles were found that fulfilled the purpose of the review. There were 36 different types of cognitive tests utilized in the included articles, with each study utilizing between one and 12 tests. The most commonly utilized cognitive test was the Mini Mental State Exam (MMSE), followed by tests of digit symbol substitution and verbal fluency. The most commonly assessed aspect of cognitive function was global cognition.

DISCUSSION

The assessment of cognitive function in older adults with CKD with standardized tests is completed in various ways. Unfortunately, the common methods of assessment of cognitive function may not be fully examining the domains of impairment commonly found in older adults with CKD. Further research is needed to identify the ideal cognitive test to best assess older adults with CKD for cognitive impairment.

The association between urbanization and reduced renal function: findings from the China Health and Nutrition Survey

BACKGROUND

While chronic kidney disease (CKD) is a growing public health concern in low- and middle-income countries, such as China, few studies have investigated the association between urbanization and the occurrence of CKD in those countries.

METHODS

We investigated the association between urbanization and estimated glomerular filtration rate (eGFR), an important CKD risk marker. Data came from the China Health and Nutrition Survey wave 2009, in which we collected fasting serum, individual and household data along with community level urbanization data, which was used to derive a study-specific urbanization measure, in 218 communities across nine provinces. A total of 3644 men and 4154 women participants aged 18 years or older were included in the analysis. Reduced renal function was defined as eGFR of less than 60 mL/min/1.73 m2 measured using serum creatinine concentration (mg/dL).

RESULTS

After adjusting for socio-demographic (e.g., age, education and household income), a sex-stratified multilevel logistic model revealed that living in a more urbanized community was associated with higher odds of reduced eGFR (odds ratio [OR] = 1.38 per one-standard deviation [SD] increase in the CHNS specific urbanization index, 95% confidence interval [CI] = 1.11-1.73 for men; OR = 1.35, 95% CI = 1.11-1.62 for women). After adjusting for behavioral variables (i.e., alcohol consumption, smoking, physical activity and diet), as well as obesity and cardiometabolic risk factors, the association was attenuated in men (OR = 1.25, 95% CI = 0.98-1.59), but remained statistically significant in women (OR = 1.24, 95% CI = 1.01-1.52).

CONCLUSION

Our findings suggest that living in an urban environment is linked with higher odds of reduced renal function independently of behavioral and cardiometabolic risk factors, which have been shown to increase along with urbanization.

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.

Chronic kidney disease and cognitive impairment among the very old in China

BACKGROUND AND AIMS

Previous studies have confirmed that chronic kidney disease (CKD) influences the cognitive function of adults. However, few studies focused the relationships among the very old. The purpose of this study was to determine whether CKD is associated with cognitive impairment among nonagenarians and centenarians in China.

METHOD

This work was conducted as a cross-sectional study. 767 unrelated Chinese nonagenarians and centenarians participated in the study. The 30-item mini-mental state examination (MMSE) was used to assess cognitive function. Estimated glomerular filtration rate (eGFR) was estimated using the Modification of Diet in Renal Disease equation (Chinese version). CKD was defined as eGFR less than 60 mL/min/1.73 m(2).

RESULTS

The cohort was 68.2 % female and mean (SD) age was 93.8 (3.5) years. There were 113 (14.7 %) and 577 (75.2 %) prevalent cases of CKD and cognitive impairment, respectively. After adjusting for sociodemographic variables, multivariate logistic regression showed CKD was not significantly associated with cognitive impairment (OR 0.81, 95 % CI 0.49-1.33). When other disease-related variables were adjusted, the result remained substantially unchanged. However, age, gender, education and income may largely or entirely explain the lack of association between CKD and cognitive impairment as measured according to the MMSE.

CONCLUSION

Among Chinese nonagenarians and centenarians, CKD was not directly correlated with cognitive impairment.

Cross-sectional study of the association between functional status and acute kidney injury in geriatric patients

BACKGROUND

Patients with chronic kidney disease tend to have impaired functional status, and this can increase the risk of morbidity and mortality. However, no previous studies have rigorously evaluated the relationship between incident acute kidney injury (AKI) and functional status of elderly patients.

METHODS

Elderly patients (≥ 65 years-old) were prospectively from the general medical wards of a single medical center in Taiwan between January, 2014 and August, 2014. These patients were divided into those with and without AKI at initial presentation, according to Kidney Disease Improving Global Outcomes (KDIGO) criteria. Functional status was assessed by Barthel Index on admission. Multiple regression analyses were utilized to investigate the relationship between AKI and functional status.

RESULTS

One hundred and fifty-two elderly patients were recruited, 38.9 % of whom had AKI. Patients with AKI at admission had significantly higher mean Charlson Comorbidity Index score (p = 0.05) and borderline lower mean Barthel Index score (34.5 vs. 43.1; p = 0.08), and a significantly lower bladder continence subscale (5.4 vs. 7.0; p = 0.05). Multiple regression analyses indicated that the presence of AKI at admission was associated with a significantly lower Barthel Index score (p = 0.04). Increasing AKI severity (higher KDIGO stage) was also associated with significantly lower Barthel Index score (p < 0.01).

CONCLUSIONS

This study documented a close relationship between AKI and functional status in the elderly. Interventions that aim to restore functional status might help to lower the risk of AKI in the elderly.

The Association of Leisure Activities in Middle Adulthood with Cognitive Performance in Old Age: The Moderating Role of Educational Level

BACKGROUND

One of the fundamental challenges for gerontological research is how to maintain and promote intact cognitive functioning in old age. Previous research revealed that high educational level, good health status, and an active lifestyle during adulthood seem to be protective against cognitive impairment in old age. However, up to now, a detailed examination of the interaction of these relations based on a broader variety of activities and considering past and current activities is missing.

OBJECTIVE

The present study set out to extend the literature by investigating in more detail the interactions of educational level and health status with a broad variety of past and current leisure activities in their association with cognitive functioning in a large sample of older adults with a wide age range.

METHODS

A total of 2,812 older adults (aged 65-101 years) served as the sample for the present study. A test on verbal abilities and one on processing speed were applied. In addition, individuals were retrospectively interviewed regarding their educational level, current general health status, and 18 leisure activities (in terms of currently performed activities and those that had been carried out at the age of 45 years).

RESULTS

Regressions indicated that engaging in more current activities and in more activities at the age of 45 years (both analyzed as an overall activity measure) was related to better cognitive performance in old age (r values up to 0.39, p values <0.001). These associations were more pronounced in individuals with a low (compared to a high) educational level.

CONCLUSION

Present results suggest that an active lifestyle during middle adulthood may be related to better cognitive functioning in old age, particularly in individuals with a low educational level. These findings are discussed with respect to models of cognitive aging.

Renal function and decline in functional capacity in older adults

BACKGROUND

longitudinal relationship between renal function, disability and mortality has not been evaluated.

OBJECTIVE

we investigated the temporal association between renal function and disability, and aimed to identify the influence of disability on mortality according to renal function in a cohort of older Koreans.

DESIGN/SETTING

Korean Longitudinal Study on Health and Aging is a prospective, population-based cohort.

SUBJECTS

community-dwelling Koreans ≥65 years of age.

MAIN OUTCOME MEASURES

Korean version of activities of daily living (ADL), Instrumental activities of daily living (IADL) and all-cause mortality.

RESULTS

a total of 984 participants were followed for 5 years with a 70.9% participation rate. The participants were categorized into three groups according to their baseline estimated glomerular filtration rates (eGFRs) (Group I, ≥60; Group II, 45-59; and Group III, <45 ml/min/1.73 m(2)). Baseline eGFR was higher in participants who maintained functional status compared with participants who died or had disability at follow-up examination. The incidence of ADL/IADL decline was 13, 12.5 and 29.5% in participants who showed improvement, no change, and decline in renal function, respectively (P = 0.01). The hazard ratio for mortality in the subgroup with IADL disability was 1.87 (95% CI: 1.10-3.20, P = 0.022) in Group I, and 2.53 (95% CI: 1.57-4.09, P<0.001) in Groups II and III after adjustment.

CONCLUSIONS

impaired renal function was related to disability and ADL/IADL decline. The effect of ADL/IADL disability on mortality was more prominent in participants with impaired eGFR.

Teamwork climate and patient safety attitudes: associations among nurses and comparison with physicians in Taiwan

The TeamSTEPPS Teamwork Attitudes Questionnaire and Safety Attitudes Questionnaire were distributed to the nurses in a county hospital in Taiwan. Nurses (n = 407) had lower scores in Team Structure, Communication, and Situation Monitoring than physicians (n = 76). A structural equation model demonstrated a positive association between teamwork climate and safety attitudes (β = 0.78, P < .01). Teamwork climate is the most important determinant for patient safety attitudes among nurses.

Mild chronic kidney disease and functional impairment in community-dwelling older adults

BACKGROUND

chronic kidney disease (CKD) has been associated with an increased risk of death and cardiovascular events, but its relationship with non-vascular outcomes, including functional impairment (FI), is less well understood.

OBJECTIVE

in this study, we review the association between CKD and FI, adjusting for potential confounders and risk factors, with a primary outcome of impairment in any instrumental ADL (IADL) or basic ADL (BADL).

DESIGN

the Cardiovascular Multimorbidity in Primary Care Study (CLARITY) is a cross-sectional study of community-dwelling adults.

SETTING

participants were adults living in the West of Ireland attending university-affiliated general practices.

SUBJECTS

all participants were adults aged ≥50 years living in the community.

METHODS

CKD was defined as an estimated glomerular filtration rate (eGFR) ≤60 ml/min/1.73 m(2). A standardised self-reported health questionnaire to measure activities of daily living (ADL) was completed by participants. Logistic regression analyses were used to determine the independent association between CKD and FI.

RESULTS

a total of 3,499 patients were included with a mean age of 66.2 ± 10.3 years. 18.0% (n = 630) had CKD (mean eGFR 50.2 ± 9.2 ml/min/1.73m(2)), 21.9% (n = 138) of which had a diagnosis of CKD documented in medical records. 40.4% (n = 1,413) reported FI and multivariable adjustment showed CKD to be independently associated with FI (OR: 1.43, 1.15-1.78), impairment in IADL (OR: 1.43, 1.15-1.78) and impairment in BADL (OR: 1.39, 1.11-1.75).

CONCLUSION

our study shows even mild CKD is associated with FI, independent of age, gender, co-morbidities, traditional vascular risk factors and cardiovascular events.

Relationship between longitudinal measures of renal function and onset of dementia in a community cohort of older adults

OBJECTIVES

To evaluate the association between dynamic measures of renal function ascertained over time and onset of dementia.

DESIGN

Prospective community cohort study.

SETTING

Group Health, Seattle, Washington.

PARTICIPANTS

Two thousand nine hundred sixty-eight adults aged 65 and older followed for the development of dementia over a median of 6.0 years (interquartile range 3.1-10.1 years).

MEASUREMENTS

Time-varying measures of renal function were constructed based on 49,340 serum creatinine measurements and included average estimated glomerular filtration rate (eGFR), eGFR trajectory, and variability in eGFR around this trajectory over 5-year exposure windows. The association between these three eGFR exposure measures and risk of dementia was estimated using a Cox regression model adjusted for other participant characteristics. Time-varying measures of urine protein by dipstick were also adjusted for in sensitivity analyses.

RESULTS

Participants with a lower eGFR had a higher incidence of dementia, but this did not reach statistical significance in adjusted analyses (omnibus P = .14). There were trends toward a higher adjusted incidence of dementia in participants with positive eGFR trajectories (omnibus P = .07) and greater variability in eGFR (omnibus P = .04) over time. The results of sensitivity analyses, including those in which time-varying measures of proteinuria were included, were consistent with those of the primary analysis.

CONCLUSION

In a community cohort of older adults followed for a median of 6 years, strong associations were not found between measures of kidney disease severity and progression and incident dementia.

Kidney function and cognitive and functional decline in elderly adults: findings from the Singapore longitudinal aging study

OBJECTIVES

To investigate whether lower estimated glomerular filtration rate (eGFR) or chronic kidney disease (CKD) was associated with subsequent cognitive and instrumental activity of daily living (IADL) decline in a prospective cohort study.

DESIGN

Prospective cohort study, followed for up to 4 years.

SETTING

General community.

PARTICIPANTS

One thousand three hundred fifteen adults aged 55 and older from the Singapore Longitudinal Aging Study.

MEASUREMENTS

Baseline data included eGFR levels, presence of CKD (eGFR < 60 mL/min per 1.73 m(2) ), and known confounders. Cognitive decline was defined as a drop of 2 or more points on the Mini-Mental State Examination (MMSE) and functional decline as a drop of 2 or more points in IADL score.

RESULTS

Decreasing levels of eGFR and the presence of CKD were associated with greater odds of cognitive decline at follow-up independent of confounding risk factors in multivariate analyses: estimated 14% increment in odds of cognitive decline per 10 mL/min/1.73 m(2) decrease in eGFR (odds ratio = 1.94, 95% confidence interval = 1.23-3.05; P = .004 for CKD vs non-CKD). Similar associations were found in a cognitively normal subgroup (MMSE > 23) at baseline. In the whole sample, CKD, but not eGFR, was found to be significantly associated with higher risk of IADL decline.

CONCLUSION

CKD in older persons was significantly associated with cognitive and functional decline. Future research should target the development and evaluation of strategies to delay or prevent cognitive decline and physical disability in elderly adults with impaired kidney function.

Is chronic kidney disease in older people a new geriatric giant?

The global population is aging, and the number of people above the age of 85 years is growing faster than any other age group. There is an age-related decline in kidney function; however, not all individuals will develop chronic kidney disease (CKD) with advancing age. Those who are genetically predisposed and exposed to lifetime cardiovascular risk factors are likely to develop systemic atherosclerosis and CKD as a part of its manifestation. CKD promotes poor health through its association with inflammation and oxidative stress. Malnutrition, weight loss and sarcopenia are common in CKD patients, leading to poor outcomes, such as physical and cognitive dysfunction, manifesting as major geriatric syndromes. Frailty is likely to be one of the underlying processes that leads to the clinical manifestations of geriatric syndromes in patients with CKD. Therefore, functional outcomes, such as cognition and physical functioning, might be more relevant outcomes to older patients with CKD. Interventions should be developed and assessed in terms of maintaining quality rather than quantity of life before disability develops.

Role of lean body mass in estimating glomerular filtration rate in Alzheimer disease

BACKGROUND

The association between estimated glomerular filtration rate (eGFR) and progression of Alzheimer disease (AD), as measured by cognitive decline and brain atrophy, has been infrequently studied. Since AD is characterized by sarcopenia and other changes in body composition, which are known to influence GFR, a determination of how lean mass (LM) affects estimation of GFR in AD patients is important.

METHODS

Participants were drawn from a prospective longitudinal study of brain ageing and AD in community-dwelling individuals. Control (n = 60) and AD (n = 61) participants were enrolled. Estimated GFR was calculated using the four-variable Modification of Diet in Renal Disease (MDRD), Cockroft-Gault, Macdonald appendicular LM and Taylor LM equations. Association of eGFR with 2-year change in cognitive function and brain volume was assessed.

RESULTS

Individuals with AD demonstrated a paradoxical finding in which lower baseline MDRD eGFR was associated with less cognitive decline (P = 0.04) and brain atrophy (P = 0.02), a phenomenon not observed in non-AD controls. This finding was abolished in the AD patients when either the Macdonald appendicular LM or Taylor LM equations were used. While significant group-by-eGFR interactions were present for cognitive decline (P = 0.006) and brain atrophy (P = 0.001) when the MDRD equation was used, no group-by-eGFR interactions were present when either the Macdonald LM (P = 0.58 and P = 0.10 for cognitive decline and brain atrophy, respectively) or Taylor LM (P = 0.97 and P = 0.55) equations were used.

CONCLUSIONS

Accounting for measures of LM in GFR estimation appears to significantly mitigate counterintuitive relationships between measures of AD progression and eGFR as calculated by more traditional measures of renal function. This suggests that consideration of LM in eGFR calculations may be important in patients with sarcopenia, such as the AD population.

Carbamylated LDL

Nonenzymatic modification of protein by cyanate, that is, carbamylation, has received new attention due to its apparent relevance in atherosclerosis. For example, carbamylation of low-density lipoprotein (LDL) is an important mechanism that potentially impacts high-risk atherosclerotic individuals with increased urea (renal insufficiency) or thiocyanate (tobacco smoking). Carbamylated LDL (cLDL) is increased in patients with end-stage kidney disease, especially those with atherosclerosis. In addition, cLDL exhibits distinct cytotoxic effects when tested in vitro on endothelial cells, induces the expression of adhesion molecules, and aggravates the monocyte adhesion to endothelial cells. It also facilitates the proliferation of vascular smooth-muscle cell (VSMC). Studies of potential pharmacological interruption of these processes in vivo may lead to discoveries of novel therapies for atherosclerosis.

Diagnosis and management of mineral metabolism in CKD

BACKGROUND

Chronic kidney disease (CKD) affects over 26 million Americans and is frequently complicated early in its course by disordered mineral metabolism and metabolic bone disease. Since CKD-related bone loss is often indistinguishable from osteoporosis by standard bone densitometry, many CKD patients may be inappropriately treated with bisphosphonates rather than CKD-specific therapies.

OBJECTIVE

To determine the prevalence of appropriate evaluation, diagnosis and management of metabolic bone disease among individuals with pre-dialysis CKD.

DESIGN AND PARTICIPANTS

Retrospective cohort study using electronic medical records of 69,215 ambulatory patients seen in the primary care clinics of an academic medical center.

MEASUREMENTS

Prevalence of CKD stages 3-4, frequency of diagnostic testing and treatment of metabolic bone disease.

MAIN RESULTS

Based on current diagnostic criteria and consistent with national data, CKD was present in 12% of the population. Bisphosphonates were used in 7.2% of patients, 20% of whom met criteria for CKD. Fewer than half of CKD patients underwent testing for parathyroid hormone (PTH) or 25-hydroxyvitamin D (25D) levels. Among those tested, vitamin D deficiency (25D <30 ng/ml) and secondary hyperparathyroidism (PTH >60 pg/ml) were present in 65% and 55%, respectively. Among patients with CKD, bisphosphonate use was nearly seven times as frequent as therapy with active vitamin D (12% vs. 1.7%, p < 0.0001), a primary treatment for CKD-associated metabolic bone disease.

CONCLUSIONS

Disordered mineral metabolism in CKD is common, under-diagnosed and under-treated. As a result, bisphosphonates may be prescribed inappropriately in patients with CKD.

Association between chronic obstructive pulmonary disease and chronic kidney disease in vascular surgery patients

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is recognized as a source of systemic inflammation and is associated with the development of cardiovascular disease. However, little is known about the association between COPD and chronic kidney disease (CKD). Therefore, we investigated the relationship between COPD and CKD and the association between COPD and mortality in patients with CKD.

METHODS

We conducted a cohort study of 3358 vascular surgery patients between 1990 and 2006. CKD was defined according to the Modification of Diet in Renal Disease equation as an estimated glomerular filtration rate (GFR) <60 mL/min/1.73 m(2). In addition, the patients were divided into three categories based on the baseline estimated GFR: > or =90 mL/min/1.73 m(2); 60-89 mL/min/1.73 m(2) and <60 mL/min/1.73 m(2). Multivariable logistic regression analysis was used to evaluate the independent association between prevalent COPD and CKD.

RESULTS

The prevalence of COPD was inversely related to kidney function. COPD was present in 47, 38 and 32% of patients with an estimated GFR <60, 60-89 and > or =90 mL/min/1.73 m(2), respectively. COPD was independently associated with CKD (OR 1.22; 95% CI 1.03-1.44; P = 0.03). This association was strongest in patients with moderate COPD (OR 1.33; 95% CI 1.07-1.65; P = 0.01). Both moderate and severe COPD were associated with increased long-term mortality in patients with CKD (HR 1.27; 95% CI 1.03-1.56; P = 0.03 and HR 1.61; 95% CI 1.10-2.35; P = 0.01, respectively), compared to patients without COPD.

CONCLUSIONS

Our findings indicate that COPD is moderately associated with CKD in a large cohort of vascular surgery patients. In addition, moderate and severe COPD are related to increased long-term mortality in patients with CKD.