Prevalence,Awareness, Treatment and Control of Diabetes Among Elderly Persons in an Urban Slum of Delhi

Background:

The increasing proportion of elderly persons is contributing to an increase in the prevalence of diabetes. The residents of urban slums are more vulnerable due to poverty and lack of access to health care.

Objective:

To estimate the prevalence of diabetes in elderly persons in an urban slum and to assess their awareness, treatment and control of this condition.

Materials and Methods:

All persons aged 60 years and above, residing in an urban slum of Delhi, were included in this cross-sectional community- based study. Data were collected on sociodemographic variables. The participants’ awareness and treatment of diabetes was recorded. Their fasting blood sugar was estimated using an automated glucometer. Diabetes was diagnosed if fasting blood glucose was ≥126 mg/dL, or if the participant was taking treatment for diabetes. Impaired fasting blood glucose was diagnosed if fasting blood glucose was 110–125 mg/dL.

Results:

Among the 474 participants studied, the prevalence of diabetes was estimated to be 18.8% (95% CI 15.3–21.5). It decreased with increasing age, and was higher among women. The prevalence of impaired fasting blood glucose was 19.8% (95% CI 16.3–23.7). It was higher among women. One-third of the diabetic participants were aware of their condition; two-thirds of these were on treatment and three-fourths of those on treatment had controlled fasting blood sugar level. The awareness, treatment and control were better among women.

Conclusions:

Diabetes is common among elderly persons in urban slums. Its magnitude and low awareness warrant effective public health interventions for their treatment and control.     

Alcohol Use and STI among Men in India: Evidences from a National Household Survey

Background:

Alcohol use has been found to correlate with risky sexual behavior as well as with sexually transmitted infections (STI) among populations with high-risk behavior in India.

Objective:

To examine the correlates of alcohol use and its association with STI among adult men in India.

Materials and Methods:

Data from a national representative large-scale household sample survey in the country were used. It included information on sociodemographic characteristics and alcohol use as a part of substance use. Clinical as well laboratory testing was done to ascertain the STI.

Results:

The overall STI prevalence among adult males was found to be 2.5% (95% confidence interval (CI): 1.9–3.1). Over 26% adult men were found to have been using alcohol in the study population. It was higher among men who were illiterate and unskilled industrial workers/drivers. The men who consumed alcohol had higher prevalence of STI (3.6%; 95% CI: 2.9–5.1) than those who did not consume alcohol (2.1%; 95% CI: 1.5–2.6). The degree of association between alcoholism and STI was slightly reduced after adjusting for various sociodemographic characteristics (adjusted odds ratio: 1.5; 95% CI: 0.9–2.3; P=0.06).

Conclusions:

The findings of present study suggest integrating alcohol risk reduction into STI/HIV prevention programmes.     

Prevalence of Common Ocular Morbidities in Adult Population of Aligarh

Aims and Objectives:

To determine the prevalence of common ocular morbidities (cataract, refractive errors, glaucoma, and corneal opacities) and their demographic and sociocultural correlates.

Settings and Design:

The present cross-sectional study was conducted in the field practice areas of the Department of Community Medicine, JNMC, AMU, Aligarh, for a period of one year, from September 2005 to August 2006.

Materials and Methods:

Systematic random sampling was done to select the required sample size. All adults aged 20 years and above in the selected households were interviewed and screened using a 6/9 illiterate ‘E’ chart. Those who could not read the ‘E’ chart were referred to the respective health training center for a complete eye examination by an ophthalmologist.

Statistical Analysis:

Chi- square test.

Results:

The prevalence of visual impairment, low vision, and blindness, based on presenting visual acuity was 13.0, 7.8, and 5.3%, respectively. The prevalence of cataract was 21.7%. Bilateral cataract was present in 16.9% of the population. Cataract was significantly associated with age, education, and fuel use. The prevalence of myopia, hypermetropia, and astigmatism was 11.5, 9.8, and 3.7%, respectively. Glaucoma was diagnosed in six patients, giving a prevalence rate of 0.9%. All the six patients of glaucoma were aged above 40 years. The prevalence of corneal opacity was 4.2%.

Conclusion:

There is a high prevalence of treatable or preventable morbidities such as cataract, refractive errors, and corneal opacity.     

Lifetime occupation and physical function: a prospective cohort study on persons aged 80 years and older living in a community

Background

Several studies have reported predictors for loss of mobility and impairments of physical performance among frail elderly people.

Aim

To evaluate the relationship between lifetime occupation and physical function in persons aged 80 years or older.

Methods

Data are from baseline evaluation of 364 subjects enrolled in the ilSIRENTE study (a prospective cohort study performed in a mountain community in Central Italy). Physical performance was assessed using the physical performance battery score, which is based on three timed tests: 4‐metre walking speed, balance, and chair stand tests. Muscle strength was measured by hand grip strength. Lifetime occupation was categorised as manual or non‐manual work.

Results

Mean age of participants was 85.9 (SD 4.9) years. Of the total sample, 273 subjects (75%) had a history of manual work and 91 subjects (25%) a history of non‐manual work. Manual workers had significant lower grip strength and physical performance battery score (indicating worse performance) than non‐manual workers. After adjustment for potential confounders (including age, gender, education, depression, cognitive performance scale score, physical activity, number of diseases, hearing impairment, history of alcohol abuse, smoking habit, and haemoglobin level), manual workers had significantly worse physical function (hand grip strength: non‐manual workers 32.5 kg, SE 1.4, manual workers 28.2 kg, SE 0.8; physical performance battery score: non‐manual workers 7.1, SE 0.4, manual workers 6.1, SE 0.2).

Conclusions

A history of manual work, especially when associated with high physical stress, is independently associated with low physical function and muscle strength in older persons.     

Effect of previous-winter mortality on the association between summer temperature and mortality in South Korea

Background

It has recently been postulated that low mortality levels in the previous winter may increase the proportion of vulnerable individuals in the pool of people at risk of heat-related death during the summer months.

Objectives

We explored the sensitivity of heat-related mortality in summer (June–August) to mortality in the previous winter (December–February) in Seoul, Daegu, and Incheon in South Korea, from 1992 through 2007, excluding the summer of 1994.

Methods

Poisson regression models adapted for time-series data were used to estimate associations between a 1°C increase in average summer temperature (on the same day and the previous day) above thresholds specific for city, age, and cause of death, and daily mortality counts. Effects were estimated separately for summers preceded by winters with low and high mortality, with adjustment for secular trends.

Results

Temperatures above city-specific thresholds were associated with increased mortality in all three cities. Associations were stronger in summers preceded by winters with low versus high mortality levels for all nonaccidental deaths and, to a lesser extent, among persons ≥ 65 years of age. Effect modification by previous-winter mortality was not evident when we restricted deaths to cardiovascular disease outcomes in Seoul.

Conclusions

Our results suggest that low winter all-cause mortality leads to higher mortality during the next summer. Evidence of a relation between increased summer heat-related mortality and previous wintertime deaths has the potential to inform public health efforts to mitigate effects of hot weather.     

Study of Childhood Obesity Among School Children Aged 6 to 12 Years in Union Territory of Puducherry

Objective:

To study the prevalence of obesity and overweight among school children in Puducherry. To identify any variation as per age, gender, place of residence and type of school.

Setting and design:

Secondary data analysis of a school-based cross sectional study in all the four regions of Puducherry.

Materials and Methods:

Children between 6 and 12 yrs were sampled using multistage random sampling with population proportionate to size from 30 clusters. Anthropometric data (BMI) was analyzed using CDC growth charts. Data was analyzed using SPSS, BMI (CDC) calculator, CI calculator and OR calculator.

Results:

The prevalence of overweight (≥85^th percentile) among children was 4.41% and prevalence of obesity (>95^th percentile) was 2.12%. Mahe region had the highest prevalence of overweight (8.66%) and obesity (4.69%). Female children from private schools and urban areas were at greater risk of being overweight and obese.

Conclusions:

Childhood obesity is a problem in Puducherry and requires timely intervention for its control.     

Hospital and Geographic Variability in Thirty‐Day All‐Cause Mortality Following Colorectal Cancer Surgery

Objective

To assess hospital and geographic variability in 30-day mortality after surgery for CRC and examine the extent to which sociodemographic, area-level, clinical, tumor, treatment, and hospital characteristics were associated with increased likelihood of 30-day mortality in a population-based sample of older CRC patients.

Data Sources/Study Setting

Linked Surveillance Epidemiology End Results (SEER) and Medicare data from 47,459 CRC patients aged 66 years or older who underwent surgical resection between 2000 and 2005, resided in 13,182 census tracts, and were treated in 1,447 hospitals.

Study Design

An observational study using multilevel logistic regression to identify hospital- and patient-level predictors of and variability in 30-day mortality.

Data Collection/Extraction Methods

We extracted sociodemographic, clinical, tumor, treatment, hospital, and geographic characteristics from Medicare claims, SEER, and census data.

Principal Findings

Of 47,459 CRC patients, 6.6 percent died within 30 days following surgery. Adjusted variability in 30-day mortality existed across residential census tracts (predicted mortality range: 2.7–12.3 percent) and hospitals (predicted mortality range: 2.5–10.5 percent). Higher risk of death within 30 days was observed for CRC patients age 85+ (12.7 percent), census-tract poverty rate >20 percent (8.0 percent), two or more comorbid conditions (8.8 percent), stage IV at diagnosis (15.1 percent), undifferentiated tumors (11.6 percent), and emergency surgery (12.8 percent).

Conclusions

Substantial, but similar variability was observed across census tracts and hospitals in 30-day mortality following surgery for CRC in patients 66 years and older. Risk of 30-day mortality is driven not only by patient and hospital characteristics but also by larger social and economic factors that characterize geographic areas.     

Influenza-associated mortality in temperate and subtropical Chinese cities, 2003-2008

Objective

To estimate influenza-associated mortality in urban China.

Methods

Influenza-associated excess mortality for the period 2003–2008 was estimated in three cities in temperate northern China and five cities in the subtropical south of the country. The estimates were derived from models based on negative binomial regressions, vital statistics and the results of weekly influenza virus surveillance.

Findings

Annual influenza-associated excess mortality, for all causes, was 18.0 (range: 10.9–32.7) deaths per 100 000 population in the northern cities and 11.3 (range: 7.3–17.8) deaths per 100 000 in the southern cities. Excess mortality for respiratory and circulatory disease was 12.4 (range: 7.4–22.2) and 8.8 (range: 5.5–13.6) deaths per 100 000 people in the northern and southern cities, respectively. Most (86%) deaths occurred among people aged ≥ 65 years. Influenza-associated excess mortality was higher in B-virus-dominant seasons than in seasons when A(H3N2) or A(H1N1) predominated, and more than half of all influenza-associated mortality was associated with influenza B virus.

Conclusion

Between 2003 and 2008, seasonal influenza, particularly that caused by the influenza B virus, was associated with substantial mortality in three cities in the temperate north of China and five cities in the subtropical south of the country.     

Influence of Socioeconomic Status on In-Hospital Mortality and Morbidity after Stroke in India: Retrospective Hospital-Based Cohort Study

Objectives:

To determine an association between socioeconomic status and in-hospital outcome in Indian patients with stroke.

Materials and Methods:

Retrospective hospital-based cohort study. The hospital stroke register was used for this study. The independent variables were demographic job status, education, cardiovascular risk factors, comorbidities and the score on the Glasgow Coma Scale (GCS). The outcome variables were mortality and Barthel′s index (BI) score at discharge.

Results:

Data of 599 consecutive patients comprising 370 men (54.3%) and 229 women (33.6%) was available for analysis. Their mean age was 55.63±15.36 years. Age, diagnosis (ischemic or hemorrhagic), midline shift, smoking and GCS were significantly associated with mortality and BI score (P<0.05). There was a statistically significant association between employment status and BI at discharge (P=0.03) in univariate analysis. In multivariate analysis, joblessness was associated with lower BI at discharge (P=0.02) after adjustment for GCS motor score and stroke subtype.

Conclusion:

Our study shows that in patients with stroke, lower employment status is associated with poor outcome at discharge from the hospital. The association is independent of other prognostic factors.     

Body mass index and mortality from all causes and major causes in Japanese: results of a pooled analysis of 7 large-scale cohort studies

Background

We pooled data from 7 ongoing cohorts in Japan involving 353 422 adults (162 092 men and 191 330 women) to quantify the effect of body mass index (BMI) on total and cause-specific (cancer, heart disease, and cerebrovascular disease) mortality and identify optimal BMI ranges for middle-aged and elderly Japanese.

Methods

During a mean follow-up of 12.5 years, 41 260 deaths occurred. The Cox proportional hazards model was used to estimate hazard ratios (HRs) for each BMI category, after controlling for age, area of residence, smoking, drinking, history of hypertension, diabetes, and physical activity in each study. A random-effects model was used to obtain summary measures.

Results

A reverse-J pattern was seen for all-cause and cancer mortality (elevated risk only for high BMI in women) and a U- or J-shaped association was seen for heart disease and cerebrovascular disease mortality. For total mortality, as compared with a BMI of 23 to 25, the HR was 1.78 for 14 to 19, 1.27 for 19 to 21, 1.11 for 21 to 23, and 1.36 for 30 to 40 in men, and 1.61 for 14 to 19, 1.17 for 19 to 21, 1.08 for 27 to 30, and 1.37 for 30 to 40 in women. High BMI (≥27) accounted for 0.9% and 1.5% of total mortality in men and women, respectively.

Conclusions

The lowest risk of total mortality and mortality from major causes of disease was observed for a BMI of 21 to 27 kg/m² in middle-aged and elderly Japanese.Key words: body mass index, mortality, cancer, heart disease, cerebrovascular disease     

Status of Iodized Salt Coverage in Urban Slums of Cuttack City, Orissa

Background:

For sustainable elimination of iodine deficiency disorders (IDD), it is necessary to consume adequately iodized salt on a regular basis and optimal iodine nutrition can be achieved through universal salt iodization.

Objective:

To assess the extent of use of adequately iodized salt in the urban slums of Cuttack.

Materials and Methods:

Using a stratified random multi-stage cluster sampling design, a cross-sectional study involving 336 households and 33 retail shops selected randomly from 11 slums of Cuttack was conducted in 2005. A predesigned pretested schedule was used to obtain relevant information and salt iodine was estimated qualitatively by using a spot testing kit and quantitatively using the iodometric titration method.

Statistical Analysis:

Proportion, Chi-square test.

Results:

Only 60.1% of the households in urban slums of Cuttack were using adequately iodized salt i.e., the iodine level in the salt was ≥15 ppm. Iodine deficiency was significantly marked in sample salts collected from katcha houses as compared with salts collected from pucca houses. Households with low financial status were using noniodized/inadequately-iodized salt. Both crystalline and refined salts were sold at all retail shops. Crystalline salts collected from all retailers had an iodine content < 15 ppm and refined salts collected from one retailer had iodine content < 15 ppm. About 48.5% of salt samples collected from retail shops were adequately iodized.

Conclusion:

In the urban slums of Cuttack, retailers were selling crystalline salts, which were inadequately iodized- this would be a setback in the progress towards eliminating IDD.     

Lifestyle and Gallstone Disease: Scope for Primary Prevention

Objective:

To study the antecedent risk factors in the causation of gallstone disease in a hospital-based case control study.

Materials and Methods:

Cases (n = 150) from all age groups and both sexes with sonographically proven gallstones were recruited over a duration of 3 months from the surgical wards of a tertiary care teaching hospital. Modes of presentation were also noted among cases. Age- and sex-matched controls (n = 150) were chosen from among ward inmates admitted for other reasons. Univariate and multivariate logistic regression analyses were performed for selected sociodemographic, dietary, and lifestyle-related variables.

Results:

Females had a higher prevalence of gallstone disease than males (P < 0.01). Among males, the geriatric age group (<60 years) was relatively more susceptible (28%). Prepubertal age group was least afflicted (3.3%). Univariate analysis revealed multiparity, high fat, refined sugar, and low fiber intakes to be significantly associated with gallstones. Sedentary habits, recent stress, and hypertension were also among the significant lifestyle-related factors. High body mass index and waist hip ratios, again representing unhealthy lifestyles, were the significant anthropometric covariates. However, only three of these, viz., physical inactivity, high saturated fats, and high waist hip ratio emerged as significant predictors on stepwise logistic regression analysis (P < 0.05).

Conclusion:

Gallstone disease is frequent among females and elderly males. Significant predictor variables are abdominal adiposity, inadequate physical activity, and high intake of saturated fats; thus representing high risk lifestyles and yet amenable to primary prevention.     

Disparities in Use of Gynecologic Oncologists for Women with Ovarian Cancer in the United States

Objective

To examine disparities in utilization of gynecologic oncologists (GOs) across race and other sociodemographic factors for women with ovarian cancer.

Data Sources

Obtained SEER-Medicare linked dataset for 4,233 non-Hispanic White, non-Hispanic African American, Hispanic of any race, and Non-Hispanic Asian women aged ≥66 years old diagnosed with ovarian cancer during 2000–2002 from 17 SEER registries. Physician specialty was identified by linking data to the AMA master file using Unique Physician Identification Numbers.

Study Design

Retrospective claims data analysis for 1999–2006. Logistic regression models were used to analyze the association between GO utilization and race/ethnicity in the initial, continuing, and final phases of care.

Principal Findings

GO use decreased from the initial to final phase of care (51.4–28.8 percent). No racial/ethnic differences were found overall and by phase of cancer care. Women >70 years old and those with unstaged disease were less likely to receive GO care compared to their counterparts. GO use was lower in some SEER registries compared to the Atlanta registry.

Conclusions

GO use for the initial ovarian cancer treatment or for longer term care was low but not different across racial/ethnic groups. Future research should identify factors that affect GO utilization and understand why use of these specialists remains low.     

Age Heaping and Accuracy of Age Data Collected During a Community Survey in the Yavatmal District, Maharashtra

Background:

Age is an important variable in epidemiological studies and an invariable part of community-based study reports.

Aims:

The aim was to assess the accuracy of age data collected during community surveys.

Settings and Design:

A cross-sectional study was designed in rural areas of the Yavatmal district.

Materials and Methods:

Age data were collected by a house-to-house survey in six villages. An open-ended questionnaire was used for data collection.

Statistical Analysis:

Age heaping and digit preference were measured by calculating Whipple’s index and Myers’ blended index. Age Ratio Scores (ARS) and Age Accuracy Index (AAI) were also calculated.

Results:

Whipple’s index for the 10-year age range, i.e., those reporting age with terminal digit “0” was 386.71. Whipple’s index for the 5-year range, i.e., those reporting age with terminal digit ‘0’ or ‘5’ was 382.74. Myer’s blended index calculated for the study population was 41.99. AAI for the population studied was 14.71 with large differences between frequencies of males and females at certain ages.

Conclusion:

The age data collected in the survey were of very poor quality. There was age heaping at ages with terminal digits ‘0’ and ‘5’, indicating a preference in reporting such ages and 42% of the population reported ages with an incorrect final digit. Innovative methods in data collection along with measuring and minimizing errors using statistical techniques should be used to ensure the accuracy of age data which can be checked using various indices.     

Effect of Impairment and Disability on Health-Related Quality of Life of Elderly: A Community-Based Study from Urban India

Introduction:

Increasing population of elderly and the emergence of epidemic of chronic or (non-communicable) diseases, which is likely to adversely affects their health-related quality of life (HRQOL), has implications on health systems in developing countries such as India. A study was conducted to know the common impairments and disabilities and their effect on HRQOL in elderly population.

Materials and Methods:

A community-based cross-sectional study on elderly, selected by cluster sampling from central Delhi, India, was conducted from April 2005 to February 2006. A pre-tested, semi-structured questionnaire, along with Short Form -36 (SF-36) survey was used for data collection. The data was analyzed using Chi square and student''s t test on SPSS v12 statistical software. P value of less than 0.05 was considered statistically significant.

Results:

A total of 200 elderly were included in the study. 71.5% subjects had at least one disability/impairment. Around 40% subjects reported their health being poor and another 50% of worsening of their health in the last 1 year. HRQOL score for people with and without chronic morbidity/disability was 51.8 and 73.5, respectively (P<0.05), with overall mean score 56.7 (±17.2). The most commonly affected HRQOL domains were Role Physical, Physical Functioning, and General Health. The HRQOL and domain scores decreased with increasing age, and females had lower mean scores than males (P<0.05).

Conclusion:

The HRQOL of elderly in urban India is severely affected by impairments and disabilities. There is an immediate need for specific preventive and rehabilitative measures targeted on elderly to maintain their health related quality of life. This information may be utilized for designing any policy and/or program targeted for elderly in India and in other similar settings.     

Predictive validity of a retrospective measure of noise exposure

Aims

To investigate the validity of measures of noise exposure derived retrospectively for a cohort of nuclear energy workers for the period 1950–98, by investigating their ability to predict hearing loss.

Methods

Subjects were men aged 45–65 chosen from a larger group of employees—assembled for a nested case‐control study of noise and death from ischaemic heart disease—who had had at least one audiogram after at least five years'' work. Average hearing loss, across both ears and the frequencies 0.5, 1, 2, and 4 kHz, was calculated from the last audiogram for each man. Previous noise exposure at work was assessed retrospectively by three hygienists using work histories, noise survey records from 1965–98, and judgement about use of hearing protection devices. Smoking and age at the time of the audiogram were extracted from records. Differences in hearing loss between men categorised by cumulative noise exposure were assessed after controlling for age, smoking, year of test, and previous test experience.

Results

There were 186 and 150 eligible subjects at sites A and B of the company respectively who were employed for an average of 20 years. Compared to men with less than one year''s exposure to levels of 85dB(A) or greater, hearing loss was greater by 3.7 dB (90% CI −2.6 to 10.1), 3.8 dB (90% CI −2.6 to 10.3), 7.0 dB (90% CI 1.1 to 12.9) and 10.1 dB (90% CI 4.2 to 16.0) in the lowest to highest categories of cumulative noise exposure at site B. In contrast, at site A, the corresponding figures were −2.2 dB, −2.4 dB, −1.8 dB, and −4.4 dB, with no confidence interval excluding zero.

Conclusions

Noise estimation at one site was shown to have predictive validity in terms of hearing loss, but not at the other site. Reasons for the differences between sites are discussed.Retrospective estimation of exposure is common in occupational epidemiology but often there is little opportunity to validate the resulting measure. However, if the exposure is already accepted to cause a particular adverse outcome, it may be possible to assess the predictive validity of the measure—that is, its ability to predict the adverse event. We developed a method¹ for retrospective estimation of noise exposure within an occupational cohort for use in a study of noise and cardiovascular mortality.² Since excessive noise can cause hearing loss,^3,4,5 and audiograms had been carried out on a sample of the cohort, an opportunity arose to investigate the predictive validity of the noise measure. We report here the results of that investigation.     

Health Benefits of Daily Walking on Mortality Among Younger-Elderly Men With or Without Major Critical Diseases in the New Integrated Suburban Seniority Investigation Project: A Prospective Cohort Study

Background

Regular physical activity contributes to the prevention of cancer, cardiovascular disease, and other chronic diseases. However, the frequency of physical activity often declines with age, particularly among the elderly. Thus, we investigated the effects of daily walking on mortality among younger-elderly men (65–74 years) with or without major critical diseases (heart disease, cerebrovascular disease, or cancer).

Methods

We assessed 1239 community-dwelling men aged 64/65 years from the New Integrated Suburban Seniority Investigation Project. We estimated hazard ratios (HRs) of all-cause mortality and 95% confidence intervals (CIs) according to daily walking duration and adjusted for potential confounders, including survey year, marital status, work status, education, smoking and drinking status, BMI, regular exercise, regular sports, sleeping time, medical status, disease history, and functional capacity.

Results

For men without critical diseases, mortality risk declined linearly with increased walking time after adjustment for confounders (P _trend = 0.018). Walking ≥2 hours/day was significantly associated with lower all-cause mortality (HR 0.49; 95% CI, 0.27–0.90). For men with critical diseases, walking 1–2 hours/day showed a protective effect on mortality compared with walking <0.5 hours/day after adjustment for confounders (HR 0.29; 95% CI, 0.06–1.20). Walking ≥2 hours/day showed no benefit on mortality in men with critical diseases, even after adjustment for confounders.

Conclusions

Different duration of daily walking was associated with decreased mortality for younger-elderly men with or without critical diseases, independent of sociodemographic and lifestyle factors, BMI, medical status, disease history, and functional capacity. Incorporating regular walking into daily lives of younger-elderly men may improve longevity and successful aging.Key words: walking, mortality, younger elderly, secondary prevention     

Low cholesterol is associated with mortality from stroke, heart disease, and cancer: the Jichi Medical School Cohort Study

Background

We investigated the relationship between low cholesterol and mortality and examined whether that relationship differs with respect to cause of death.

Methods

A community-based prospective cohort study was conducted in 12 rural areas in Japan. The study subjects were 12 334 healthy adults aged 40 to 69 years who underwent a mass screening examination. Serum total cholesterol was measured by an enzymatic method. The outcome was total mortality, by sex and cause of death. Information regarding cause of death was obtained from death certificates, and the average follow-up period was 11.9 years.

Results

As compared with a moderate cholesterol level (4.14–5.17 mmol/L), the age-adjusted hazard ratio (HR) of low cholesterol (<4.14 mmol/L) for mortality was 1.49 (95% confidence interval [CI]: 1.23–1.79) in men and 1.50 (1.10–2.04) in women. High cholesterol (≥6.21 mmol/L) was not a risk factor. This association was unchanged in analyses that excluded deaths due to liver disease, which yielded age-adjusted HRs of 1.38 (95% CI, 1.13–1.67) in men and 1.49 (1.09–2.04) in women. The multivariate-adjusted HRs and 95% CIs of the lowest cholesterol group for hemorrhagic stroke, heart failure (excluding myocardial infarction), and cancer mortality significantly higher than those of the moderate cholesterol group, for each cause of death.

Conclusions

Low cholesterol was related to high mortality even after excluding deaths due to liver disease from the analysis. High cholesterol was not a risk factor for mortality.Key words: low cholesterol, mortality, liver disease, stroke, heart disease, cohort study     

Heat waves in the United States: mortality risk during heat waves and effect modification by heat wave characteristics in 43 U.S. communities

Background

Devastating health effects from recent heat waves, and projected increases in frequency, duration, and severity of heat waves from climate change, highlight the importance of understanding health consequences of heat waves.

Objectives

We analyzed mortality risk for heat waves in 43 U.S. cities (1987–2005) and investigated how effects relate to heat waves’ intensity, duration, or timing in season.

Methods

Heat waves were defined as ≥ 2 days with temperature ≥ 95th percentile for the community for 1 May through 30 September. Heat waves were characterized by their intensity, duration, and timing in season. Within each community, we estimated mortality risk during each heat wave compared with non-heat wave days, controlling for potential confounders. We combined individual heat wave effect estimates using Bayesian hierarchical modeling to generate overall effects at the community, regional, and national levels. We estimated how heat wave mortality effects were modified by heat wave characteristics (intensity, duration, timing in season).

Results

Nationally, mortality increased 3.74% [95% posterior interval (PI), 2.29–5.22%] during heat waves compared with non-heat wave days. Heat wave mortality risk increased 2.49% for every 1°F increase in heat wave intensity and 0.38% for every 1-day increase in heat wave duration. Mortality increased 5.04% (95% PI, 3.06–7.06%) during the first heat wave of the summer versus 2.65% (95% PI, 1.14–4.18%) during later heat waves, compared with non-heat wave days. Heat wave mortality impacts and effect modification by heat wave characteristics were more pronounced in the Northeast and Midwest compared with the South.

Conclusions

We found higher mortality risk from heat waves that were more intense or longer, or those occurring earlier in summer. These findings have implications for decision makers and researchers estimating health effects from climate change.