Health-Adjusted Life Expectancy among Canadian Adults with and without Hypertension

Burden of CKD and Cardiovascular Disease on Life Expectancy and Health Service Utilization: a Cohort Study of Hong Kong Chinese Hypertensive Patients

BACKGROUND

The relative effects of combinations of CKD, heart disease, and stroke on risk of mortality, direct medical costs, and life expectancy are unknown.

METHODS

In a retrospective cohort study of 506,849 Chinese adults in Hong Kong with hypertension, we used Cox regressions to examine associations between all-cause mortality and combinations of moderate CKD (eGFR of 30-59 ml/min per 1.73 m²), severe CKD (eGFR of 15-29 ml/min per 1.73 m²), heart disease (coronary heart disease or heart failure), and stroke, and modeling to estimate annual public direct medical costs and life expectancy.

RESULTS

Over a median follow-up of 5.8 years (2.73 million person-years), 55,666 deaths occurred. Having an increasing number of comorbidities was associated with incremental increases in mortality risk and medical costs and reductions in life expectancy. Compared with patients who had neither CKD nor cardiovascular disease, patients with one, two, or three conditions (heart disease, stroke, and moderate CKD) had relative risk of mortality increased by about 70%, 160%, and 290%, respectively; direct medical costs increased by about 70%, 160%, and 280%, respectively; and life expectancy at age 60 years decreased by about 5, 10, and 15 years, respectively. Burdens were higher with severe CKD.

CONCLUSIONS

This study demonstrated extremely high mortality risk and medical cost increases for severe CKD, exceeding the combined effects from heart disease and stroke. Mortality risks and costs for moderate CKD, heart disease, and stroke were similar individually and roughly multiplicative for any combination. These findings suggest that to reduce mortality and health care costs in patients with hypertension, CKD prevention and intervention merits priority equal to that of cardiovascular disease.

Standard Period Life Table Used to Compute the Life Expectancy of Diseased Subpopulations: More Confusing Than Helpful

Life expectancy (LE) based on a period life table (PLT) traditionally serves as a general population summary metric. It is, however, becoming more frequently reported for chronically afflicted subpopulations. In general populations, there is always an obvious real cohort sharing the hypothetical PLT cohort characteristics, and the LE estimate is intuitively understood as that real cohort mean survival time, assuming constancy of death risks. In diseased subpopulations, the correspondence between the hypothetical cohort and a real cohort is not straightforward. Furthermore, the excess mortality of chronic diseases usually changes according to age at onset and time since onset. The standard PLT method does not allow for proper control of these issues, so the LE estimate can only be deemed valid under specific assumptions. Without clear statements about the real cohort to whom the estimate is intended and the assumptions allowing disregard of the effect of age at onset and time since onset, LEs of afflicted subpopulations computed with the PLT are only abstract numbers summarizing mortality rates. If called "life expectancy," they can be seriously misleading. The same applies to health-adjusted LE.

Prevalence of chronic kidney disease associated with cardiac and vascular complications in hypertensive patients: a multicenter, nation-wide study in Thailand

BACKGROUND

Hypertension and chronic kidney disease (CKD) are common conditions and both are major risk factors for cardiovascular events. The objectives were 1) to study the prevalence of CKD in hypertensive patients and 2) to study the association of CKD with cardiac and vascular complications in a multicenter, nation-wide fashion.

METHODS

This cross-sectional study evaluated patients aged 20 years or older who were diagnosed with hypertension and who had been treated for at least 12 months at 831 public hospitals in Thailand during the 2012 study period. Outcome measurements included calculated glomerular filtration rate (GFR) and cardiac and vascular complications that included coronary artery disease, stroke, peripheral arterial disease, heart failure, and atrial fibrillation. Multivariable modeling was conducted to determine independent factors associated with increased risk of cardiac and vascular complications.

RESULTS

A total of 28770 patients were enrolled. Average age was 62.8 years and 37% were male. Prevalence of CKD stage 3 and 4-5 was 33.2 and 4.3%, respectively. Prevalence of cardiac and vascular complications was 10.5% (5% having coronary artery disease, 3.9% stroke, 1.7% heart failure, and 1.2% atrial fibrillation). CKD was an independent risk factor associated with each of the complications and overall cardiac and vascular complications with an adjusted Odds ratio of 1.4 for CKD stage 3 and 1.9 for CKD stage 4-5.

CONCLUSION

Prevalence of CKD stage 3-5 in hypertensive population was 37.5%. CKD is an independent risk factor for adverse cardiac and vascular outcome.

Kidney function, albuminuria and life expectancy

BACKGROUND

Lower estimated glomerular filtration rate is associated with reduced life expectancy. Whether this association is modified by the presence or absence of albuminuria, another cardinal finding of chronic kidney disease, is unknown.

OBJECTIVE

Our objective was to estimate the life expectancy of middle-aged men and women with varying levels of eGFR and concomitant albuminuria.

DESIGN

A retrospective cohort study.

SETTING

A large population-based cohort identified from the provincial laboratory registry in Alberta, Canada.

PARTICIPANTS

Adults aged ≥30 years who had outpatient measures of serum creatinine and albuminuria between May 1, 2002 and March 31, 2008.

MEASUREMENTS

PREDICTOR

Baseline levels of kidney function identified from serum creatinine and albuminuria measurements.

OUTCOMES

all cause mortality during the follow-up.

METHODS

Patients were categorized based on their estimated glomerular filtration rate (eGFR) (≥60, 45-59, 30-44, and 15-29 mL/min/1 · 73 m(2)) as well as albuminuria (normal, mild, and heavy) measured by albumin-to-creatinine ratio or urine dipstick. The abridged life table method was applied to calculate the life expectancies of men and women from age 40 to 80 years across combined eGFR and albuminuria categories. We also categorized participants by severity of kidney disease (low risk, moderately increased risk, high risk, and very high risk) using the combination of eGFR and albuminuria levels.

RESULTS

Among men aged 50 years and with eGFR ≥60 mL/min/1.73 m(2), estimated life expectancy was 24.8 (95% CI: 24.6-25.0), 17.5 (95% CI: 17.1-17.9), and 13.5 (95% CI: 12.6-14.3) years for participants with normal, mild and heavy albuminuria respectively. Life expectancy for men with mild and heavy albuminuria was 7.3 (95% CI: 6.9-7.8) and 11.3 (95% CI: 10.5-12.2) years shorter than men with normal proteinuria, respectively. A reduction in life expectancy was associated with an increasing severity of kidney disease; 24.8 years for low risk (95% CI: 24.6-25.0), 19.1 years for moderately increased risk (95% CI: 18.7-19.5), 14.2 years for high risk (95% CI: 13.5-15.0), and 9.6 years for very high risk (95% CI: 8.4-10.8). Among women of similar age and kidney function, estimated life expectancy was 28.9 (95% CI: 28.7-29.1), 19.8 (95% CI: 19.2-20.3), and 14.8 (95% CI: 13.5-16.0) years for participants with normal, mild and heavy albuminuria respectively. Life expectancy for women with mild and heavy albuminuria was 9.1 (95% CI: 8.5-9.7) and 14.2 (95% CI: 12.9-15.4) years shorter than the women with normal proteinuria, respectively. For women also a graded reduction in life expectancy was observed across the increasing severity of kidney disease; 28.9 years for low risk (95% CI: 28.7-29.1), 22.5 years for moderately increased risk (95% CI: 22.0-22.9), 16.5 years for high risk (95% CI: 15.4-17.5), and 9.2 years for very high risk (95% CI: 7.8-10.7).

LIMITATIONS

Possible misclassification of long-term kidney function categories cannot be eliminated. Possibility of confounding due to concomitant comorbidities cannot be ruled out.

CONCLUSION

The presence and degree of albuminuria was associated with lower estimated life expectancy for both gender and was especially notable in those with eGFR ≥30 mL/min/1.73 m(2). Life expectancy associated with a given level of eGFR differs substantially based on the presence and severity of albuminuria.

Chronic kidney disease and cardiovascular risk: epidemiology, mechanisms, and prevention

Since the first description of the association between chronic kidney disease and heart disease, many epidemiological studies have confirmed and extended this finding. As chronic kidney disease progresses, kidney-specific risk factors for cardiovascular events and disease come into play. As a result, the risk for cardiovascular disease is notably increased in individuals with chronic kidney disease. When adjusted for traditional cardiovascular risk factors, impaired kidney function and raised concentrations of albumin in urine increase the risk of cardiovascular disease by two to four times. Yet, cardiovascular disease is frequently underdiagnosed and undertreated in patients with chronic kidney disease. This group of patients should, therefore, be acknowledged as having high cardiovascular risk that needs particular medical attention at an individual level. This view should be incorporated in the development of guidelines and when defining research priorities. Here, we discuss the epidemiology and pathophysiological mechanisms of cardiovascular risk in patients with chronic kidney disease, and discuss methods of prevention.

Impact of diabetes mellitus on life expectancy and health-adjusted life expectancy in Canada

The objectives of this study were to estimate life expectancy (LE) and health-adjusted life expectancy (HALE) for Canadians with and without diabetes and to evaluate the impact of diabetes on population health using administrative and survey data.Mortality data from the Canadian Chronic Disease Surveillance System (2004 to 2006) and Health Utilities Index data from the Canadian Community Health Survey (2000 to 2005) were used. Life table analysis was applied to calculate LE, HALE, and their confidence intervals using the Chiang and the adapted Sullivan methods.LE and HALE were significantly lower among people with diabetes than for people without the disease. LE and HALE for females without diabetes were 85.0 and 73.3 years, respectively (males: 80.2 and 70.9 years). Diabetes was associated with a loss of LE and HALE of 6.0 years and 5.8 years, respectively, for females, and 5.0 years and 5.3 years, respectively, for males, living with diabetes at 55 years of age. The overall gains in LE and HALE after the hypothetical elimination of prevalent diagnosed diabetes cases in the population were 1.4 years and 1.2 years, respectively, for females, and 1.3 years for both LE and HALE for males.The results of the study confirm that diabetes is an important disease burden in Canada impacting the female and male populations differently. The methods can be used to calculate LE and HALE for other chronic conditions, providing useful information for public health researchers and policymakers.