Recent Population Studies Research Articles

Alcohol and cardiovascular disease--more than one paradox to consider. Type of alcoholic beverage and cardiovascular disease--does it matter?

While a large number of studies have shown a U- or J-shaped relation between alcohol intake and cardiovascular disease, the question remains whether this risk function persists in all subsets of the population or derives from all types of alcoholic beverages. Recent large population studies have suggested that the effect of alcohol and cardiovascular disease and all cause mortality is modified by factors such as age, gender, cardiovascular risk factor status, drinking pattern and type of alcohol. The author reviews the studies indicating this effect modification, while focusing on the potential beverage specific differences. The review goes through several of the methodological issues in studying the effects of the different types of beverages on health, and gives some of the plausible biological mechanisms that might explain the differences, but stresses the different biases, which are the reasons why the issue is not settled yet.

Low goitre prevalence among users of oral contraceptives in a population sample of 3712 women.

Goitre occurs primarily in women. As oestrogens may be an aetiologic factor, the use of oral contraceptives (OC) could be associated with an increased risk of goitre. This is supported by experimental data, but a recent population study suggested decreased thyroid volumes among users of OC. Cross-sectional, observational study. A random population sample of 3712 women from two Danish cities. Ultrasound and clinical examination of the thyroid, measurement of serum TSH, T3, T4 and thyroglobulin, and personal interviews with registration of use of OC or post-menopausal oestrogen therapy. Data were analysed in linear models and logistic regression adjusting for age and iodine status. Thyroid volume was lower among users than non-users of OC, 11.1 ml vs. 12.1 ml (P < 0.001). Use of OC was correspondingly associated with a reduced prevalence of thyroid enlargement on ultrasound (odds ratio 0.53, 95% confidence interval 0.37-0.74) and of palpable and visible goitre (OR 0.24, 95% CI 0.07-0.81). Serum TSH was 1.24 mU/l in non-users of OC and 1.35 mU/l in users (P = 0.002). The percentage of goitre cases prevented by OC compared to a hypothetical population without use of OC was 29%. Post-menopausal oestrogen therapy showed similar, but statistically non-significant, associations. Use of oral contraceptives was associated with a lower thyroid volume and reduced risk of goitre, and clinically evident goitre was four times more frequent among non-users than among users of oral contraceptives.

Independent and Interactive Association of Blood Antioxidants and Oxidative Damage in Elderly People

Oxidative stress is recognized as one of the major contributors to the increased risk of several diseases. Many recent population studies have established a close link between antioxidant defense and lowered risk of morbidity and mortality from cancer and heart disease, but little is known about the cooperative interactions of antioxidants. We examined the cross-sectional independent and interactive association of serum lipid-soluble antioxidant levels and free radical scavenging enzymes to serum malondialdehyde (MDA) levels, as a marker of oxidative damage. The participants were 160 nonsmoker institutionalized elderly. Upper tertile values of erythrocyte-superoxide-dismutase (E-SOD) constituted the strongest-associated single compound with a 74% decreased risk of high MDA. Upper tertiles of carotenoids and f -tocopherol independently showed a similar lowering of risk of about 57%. The highest tertiles of lycopene and either g -carotene or f -tocopherol simultaneously reveal a higher decreased risk for oxidative damage (74 and 71%, respectively), very similar to those in the upper tertiles of all these three vitamins (75%). This study represents one of the few attempts to date to understand the interactive effect between antioxidants and suggests that lipid-soluble antioxidants act not individually, but rather cooperatively with each other. The efficacy of this interaction is more effective when lycopene is present.

Psychiatric disorders and associated factors in cancer: results of an interview study with patients in inpatient, rehabilitation and outpatient treatment

An association between mental disorders, especially affective and anxiety disorders, and cancer has been reported in many studies. The present study investigated current (4-weeks-, 12-months-, and lifetime-prevalence rates of comorbid mental disorders in cancer patients. Through a cross-sectional design, 517 patients (75% female patients) from two acute inpatient care clinics, two rehabilitation clinics and nine specialised practices for oncology were examined with standardised scales for psychological burden and quality of life. Somatic parameters were assessed through standardised medical records. In the second-stage-examination, a sample of 200 patients was interviewed with standardised clinical interview (CIDI) in order to obtain DSM-IV diagnoses of mental disorders. Differences in the type of mental disorders were examined for gender, treatment setting, severity of cancer and physical impairment. Prevalence rates of mental disorders were 23.5% for the 4-weeks, 40% for the 12-months, and 56.5% for the lifetime periods. The current and 12-months rates of affective and anxiety disorders were approximately 25–33% higher than prevalence rates found in recent epidemiological studies of the general population. These higher rates were, however, mainly due to the preponderance of female patients with a higher risk for mental disorders compared with males. The most prevalent current disorders were affective (9.5%), and anxiety disorders (13%). Female gender was associated with an approximately 2-fold risk of mental disorders during the patient's lifespan. Current diagnosis of affective disorders in women was highly related to the cancer. Physical impairment was also associated with the frequency of current psychiatric disorders, especially affective and anxiety disorders. The frequency of mental disorders in cancer patients does not differ from results of recent international epidemiological studies of the normal population. The slightly higher rates of anxiety disorders are mainly due to phobias (simple, social and agoraphobia) without urgent need for treatment. A relatively large portion of patients, however, fulfil the criteria of minor depressive disorder which deserves clinical attention.

Sudden cardiac death, genes, and arrhythmogenesis : consideration of new population and mechanistic approaches from a national heart, lung, and blood institute workshop, part I.

Malignant ventricular arrhythmias are the leading mechanism of death in patients with acute and chronic cardiac pathologies. The extent to which inherited mutations and polymorphic variation in genes determining arrhythmogenic mechanisms affect these patients remains unknown, but based on recent population studies, this risk appears significant, deserving much greater investigation. This report summarizes a National Heart, Lung, and Blood Institute workshop that considered sources of genetic variation that may contribute to sudden cardiac death in common cardiac diseases. Evidence on arrhythmogenic mechanisms in recent population studies suggests a significant portion of the risk of sudden cardiac death in such broad populations may be unrelated to traditional risk factors for predisposing conditions such as atherosclerosis, hypertension, and diabetes and instead may involve unrecognized genetic and environmental interactions that influence arrhythmic susceptibility more directly. Additional population and genetic studies directed at discovering the sources of inherited molecular risk that are most directly linked to arrhythmia initiation and propagation, in addition to studies on previously well-described risk factors, would appear to have considerable potential for reducing premature cardiovascular mortality.

Will hearing healthcare be affordable in the new millennium.

Calculations of the needs of healthcare, hearing healthcare included, are usually based on clinical data rather than on valid prevalence figures. According to our recent population study, the number of citizens needing hearing aids in Finland will be twice the figure usually presented, 280 000 for the country as a whole (population 5.1 million). The penetration of hearing aids was only 41%. Taking this and the ageing of the population into account, the economic challenges of hearing healthcare will be alarming in the new millennium.

Comorbid psychiatric disorders in cancer patients in acute inpatient treatment and medical rehabilitation

An association between mental disorders, especially affective and anxiety disorders, and cancer has been reported in many clinical studies with inpatients. However, no data exist about the prevalence of mental disorders in patients undergoing acute care or rehabilitation treatment for cancer in Germany. The present study investigated 4-week, 6-month and lifetime prevalence rates of comorbid mental disorders in cancer. 256 patients from 2 rehabilitation clinics and 2 acute care hospitals were examined with standardized screening scales for psychological burden (GHQ-12, HADS) and quality of life (SF-36). Somatic parameters and interventions were assessed through standardized medical records from the attending oncologists. In the second-stage examination a subsample of 120 patients were interviewed with standardized clinical interview (CIDI) in order to obtain DSM-IV diagnoses of mental disorders. 44% (acute care) and 49% (rehabilitation) of the patients have high GHQ scores (cut-off > 4). Furthermore, more than 20% of the cancer patients have elevated scores on the HADS subscales depression and anxiety (cut-off > or = 11). Prevalence rates of mental disorders in the rehabilitation sample are 34% for the 4-week (vs. 24% in the acute care sample), 45% for the 6-month period (vs. 38%), and 79% for lifetime (vs. 49% in the acute care sample). The most frequent current disorders are affective (13% rehabilitation vs. 11% acute care) and anxiety disorders (17% in both samples). The rates of affective and anxiety disorders are much higher than the frequency of these disorders in recent epidemiological studies of the normal population in Germany. The high psychosocial burden expressed by the patients and the frequency of depressive and anxiety disorders emphasize the importance of (1) effective diagnostic strategies to recognize mental disorders, and (2) specialized psychosocial services in oncology, which provide psychological support and effective interventions for cancer patients in acute care and rehabilitation.

Dr. Breslau and Colleagues Reply

Back to table of contents Previous article Next article Letter to the EditorFull AccessDr. Breslau and Colleagues ReplyNAOMI BRESLAU, PH.D., EDWARD L. PETERSON, PH.D., RONALD C. KESSLER, PH.D., and LONNI R. SCHULTZ, PH.D., NAOMI BRESLAUSearch for more papers by this author, PH.D., EDWARD L. PETERSONSearch for more papers by this author, PH.D., RONALD C. KESSLERSearch for more papers by this author, PH.D., and LONNI R. SCHULTZSearch for more papers by this author, PH.D., Detroit, Mich.Published Online:1 Jun 2000AboutSectionsView EPUB ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InEmail Dr. Mossman correctly interprets the positive and negative predictive values in Table 3 of our article—namely, the values of those who scored four or more on our scale (defined as cases). A total of 29% did not have PTSD according to the clinical assessment, whereas of those who scored four or more (defined as noncases), 2% did have PTSD according to the clinical assessment. Despite our awareness of the common tendency to confuse positive and negative predictive values with sensitivity and specificity, we regret that we did not avoid this pitfall and that we misstated the positive and negative predictive values as if they were sensitivity and specificity (i.e., using as denominators the number of cases and noncases defined by the clinical assessment instead of by a score of four or more on the screening scale).However, we disagree with Dr. Mossman in his emphasis on sensitivity and specificity instead of on positive and negative predictive values. The latter constructs are of considerable utility for potential users, who wish to know what proportion of persons identified as cases by the scale would be confirmed by clinical examination.We wish to emphasize that the prevalence of PTSD in our study is typical of that in recent general population studies, such as the National Comorbidity Survey. Therefore, estimates of the performance of the scale based on this prevalence estimate are useful.Our recommended cutoff of four or more symptoms was based on the data for both positive and negative predictive values in Table 3. We considered the fact that positive predictive value diminishes rapidly with lower cutoffs (i.e., two or three), whereas the accompanying improvement in negative predictive value is slight. If we were to use a cutoff of two or three instead of four, the number of identified cases that would not be confirmed would double or triple. FiguresReferencesCited byDetailsCited ByNone Volume 157Issue 6 June 2000Pages 1026-a-1026 Metrics History Published online 1 June 2000 Published in print 1 June 2000

Of metals, mice, and men: what animal models can teach us about body iron loading.

Of metals, mice, and men: what animal models can teach us about body iron loading.

Progeny testing of heterozygote carriers of the Robertsonian translocation 1/29 in bovidae

In our recent population study, 220 daughters of a heterozygote carrier of the Robertsonian translocation 1/29 were analysed by screening of metaphase spreads and typing of microsatellite markers. The segregation between markers near the centromere of chromosomes 1 and 29 and the fusion were analysed. The microsatellite markers were selected from the USDA, MARC cattle genome map. Analyses were done on AGLA17, BM6438, TGLA49, BMS 1928, BM8139, INRA117, BMS574, BMS7I1 and BMS4015 of chromosome 1, and on BM4602, BMC2228 and BMS1857 of chromosome 29. The two markers BMC2228 and BMS4018 in the linkage group originating from the fusion were able to either recognise or exclude 167 daughters out of 220 as carriers of the Robertsonian translocation 1/29. Fifty‐three daughters showed double heterozygote markers like their father, and were therefore not informative. The use of conventional cytogenetics in combination with molecular studies has allowed a more precise evaluation of the Robertsonian translocations than either approach alone might have done.

Haemoglobin function in aquatic animals: molecular adaptations to environmental challenge

The adaptive nature of haemoglobin function in a diverse range of aquatic ectothermic vertebrates is demonstrated by its intrinsic oxygen-binding properties and by erythrocyte cofactor modulation of Hb function. The selective advantage of heterogeneous isohaemoglobins and polymorphic expression of functionally distinct components is considered in relation to environmental oxygen tensions and temperature. The difficulty of comparing physiological adaptations in divergent species is emphasized. Recent population studies suggest that relatively minor differences in environmental conditions, particularly temperature, direct the expression of functionally heterogeneous haemoglobins, although the thresholds for expression have not been established. Regulatory mechanisms underpinning the molecular mechanisms for hypoxic induction of Hb in aquatic vertebrates are not well understood.

Grandmultiparity: Is It a Perinatal Risk?

Increased parity is more common in lower-socioeconomic groups. Additionally, GMPs tend to be older. It is for these reasons that there is a tendency for an increased incidence of antenatal complications, such as hypertension and diabetes, among GMP mothers. It appears that the previous conflicting reports on the effect of high parity on perinatal outcome can be related to differences in the socioeconomic conditions of the parturient population under examination. Previous evidence of the unfavorable influence on perinatal outcome of high parity might have been biased by patient selection, because high parity is often inversely linked to social class. Our recent studies of the Israeli maternal population plus comparable reports from other countries allow us to conclude that GMP is not always a great cause for concern in an economically stable and healthy population that has access to high-quality medical care. As such, the term dangerous multipara should be removed from the medical literature and the focus of concern should shift to the organization and the delivery of quality medical services.

Acute intermittent porphyria.

Acute intermittent porphyria (AIP) is transmitted as an autosomal dominant disorder with incomplete penetrance. Recent population studies suggest that the prevalence of asymptomatic heterozygotes for a mutant AIP gene may be in the range of 1 in 2,000. Clinical manifestations include abdominal pain and neurological dysfunctions. These symptoms occur during acute attacks, which are often precipitated by drugs, alcohol, low caloric intake, or infections. Biochemical abnormalities are thought to result from primary defects of porphobilinogen deaminase (PBGD; also called hydroxymethyl bilane synthase), the third enzyme of the heme synthesis pathway, and consecutive hepatic overexpression of the first enzyme of the pathway, 5-aminolevulinate synthase. As a result of these enzymatic disturbances, heme precursors are synthesized in excess in the liver, and massive amounts of compounds upstream of the enzymatic block are excreted in urine. Although the pathophysiology of the disease has not yet been fully elucidated, a specific treatment of acute attacks with heme has improved the prognosis. The cDNAs and the gene encoding PBGD have been isolated, permitting identification of mutations that account for the corresponding enzymatic deficiencies. Consequently, DNA analysis improves the accuracy of detection of presymptomatic heterozygotes in AIP families, permitting better counseling.

Vocalisations of the Marbled Frogmouth I: Descriptions and an Analysis of Sex Differences

SummaryThe Marbled Frogmouth Podargus ocellatus is an elusive and rarely encountered species found in separate populations in north Queensland and in southern Queensland and northern New South Wales. Recent studies of the southern population have been largely based on detecting the presence of the bird by its vocal response to playback. At present very little is known of the vocal behaviour of the species. This paper described in detail the three most common vocalisations produced by birds in southern Queensland: the Toad, Gobble and Kerloo calls. Distinctive differences between the sexes were found for both Gobble and Kerloo calls.

The role of ambulatory blood pressure monitoring in clinical practice.

The introduction of noninvasive techniques for the repetitive measurement of blood pressure in ambulant subjects has permitted improved precision in the assessment of hypertension during normal daily life. The traditional clinic (or "office") method of blood pressure measurement has the advantages of simplicity and low cost, and forms the basis of the current operational definitions of hypertension, but it is limited by the normal variability of blood pressure and the "white coat effect." By contrast, ambulatory blood pressure provides information on circadian variations in blood pressure and alterations due to changes in behavior, and may, therefore, be more appropriate for diagnosing hypertension. However, it is important to note that the values used to define normotension and hypertension for clinic blood pressure are not appropriate for ambulatory blood pressure. Recent population studies have proposed that the upper limit for 24-h ambulatory pressure should be 119 to 126/75 to 80 mm Hg, and failure to recognize this may account for at least some cases of "white-coat hypertension." There is increasing evidence that ambulatory blood pressure is more effective than clinic blood pressure in predicting the organ damage associated with hypertension, whereas data from intervention studies indicate that a reduction in ambulatory pressure is correlated with a reduction in left ventricular (LV) mass. Finally, ambulatory blood pressure measurements may provide a number of advantages in the development of antihypertensive therapies: by permitting better identification of trough and peak effects, by confirming that the efficacy of formulations for once-daily dosing is maintained throughout the 24-h period, and by minimizing the placebo effect.

Multiphasic models of survival: analysis of mortality rate change regions and the issue of finite species lifespan.

Recent large-scale experimental population studies have allowed us to probe the dynamics of survival in the "oldest old" of a small number of biological species. The results of these studies add strong support to the validity of a multiphasic survival/mortality model for population survival as has been previously proposed by a number of investigators. In this paper we briefly review some of the problems with the Gompertz survival model, and the issue of locating the region in which the mortality rate might change. We derive some rigorous formulae for bounding the mortality rate change regions and compare the predictions to the available experimental data. We demonstrate that the mortality cut point parameter appears to be directly related to topological properties of the species survival curve, in particular, the inflection time. We conclude by addressing some of the pitfalls of using a mortality cut point model and propose an alternative formulation for a mortality model involving multiphasic mortality dynamics and incorporating a nonspecified upperbound on species lifespan.

Hypertension awareness, treatment and control in the community: is the ‘rule of halves’ still valid?

One of the cornerstones of the primary prevention of cardiovascular disease has been screening and early antihypertensive drug treatment of patients with high blood pressure (BP). Nevertheless, recent population studies have shown that awareness and management of high BP levels are far from optimal. In this study, we performed a search for publications providing frequencies of hypertension awareness, treatment and control in different populations. In men, the frequencies of awareness, antihypertensive drug treatment and BP control among all hypertensive patients varied between 23% and 93%, 5% and 89% and 5% and 87%, respectively. In women, the frequencies ranged between 28% and 97%, 6% and 97%, and 0% and 97%, respectively. The percentage of aware hypertensives who were under antihypertensive drug treatment varied between 47% and 95% in men and between 50% and 100% in women. The percentage of hypertensives who were under antihypertensive drug treatment varied between 47% and 95% in men and between 50% and 100% in women. The percentage of treated hypertensives achieving an adequate BP control varied between 29% and 95% in men and between 0% and 100% in women. Overall, women had a better awareness, treatment and control status for hypertension than men, and worse in developing countries than in industrialised countries. Hypertension awareness, treatment and control improved with time, together with the proportion of diagnosed hypertensive patients under treatment and the proportion of well controlled among treated hypertensive patients. We conclude that although the 'rule of halves' no longer applies for screening and treatment of hypertension in industrialised countries, it might still be valid for developing countries and for the effectiveness of antihypertensive drug treatment in all countries.

Hearing loss in former prisoners of war of the Japanese.

To describe the prevalence, degree, and types of hearing loss present in a group of older American veterans who had been prisoners of war of the Japanese. A descriptive study. A Veterans Affairs university hospital. Seventy-five male veterans, mean age 68 (+/- 3.6) years. Hearing aids were prescribed for eight veterans. Subjects were examined, and pure tone air and bone conduction, speech reception threshold, and speech discrimination were determined. Results were compared with age- and sex-matched controls from the largest recent American population study of hearing loss. 95% of subjects had been imprisoned longer than 33 months. Starvation conditions (100%), head trauma (85%), and trauma-related loss of consciousness (23%) were commonly reported. A total of 73% complained of hearing loss, and 29% (22/75) dated its onset to captivity. Most of those with the worst losses in hearing and speech discrimination were found in this subgroup. When the entire group was compared with published age- and sex-matched controls from the Framingham Study, no significant differences were found. We advocate screening examinations and long-term follow-up of populations with similar histories of starvation, head trauma, and torture.

Recruitment and retention of homeless mentally ill participants in research.

Are the unstable residential and personal lives of homeless mentally ill (HMI) individuals so difficult as to preclude their inclusion in rigorous, longitudinal research protocols? The continued presence of HMI individuals in U.S. society has prompted the mental health research community to reconsider the question of whether clinical trial and demonstration research protocols are feasible with this population. This article briefly examines the existing research literature on recruitment and retention rates in recent studies of this population and, in more detail, the specific strategies used by researchers to recruit and retain HMI individuals as research participants. In general, with sufficient resources and the persistent use of existing strategies for recruitment and retention, HMI individuals can be successfully studied over time. Finally, to demonstrate this potential, the recruitment and retention strategies of the San Diego McKinney Homeless Mentally Ill Demonstration Research Program are described.

DNA Repair Capacity for Ultraviolet Light-Induced Damage Is Reduced in Peripheral Lymphocytes from Patients with Basal Cell Carcinoma

Sunlight exposure and certain host factors such as red hair and fair skin are established risk factors for non-melanoma skin cancers. Because deficient DNA repair capacity has contributed to the development of skin cancers in a rare genetic disease, xeroderma pigmentosum, we explored this deficiency as an etiologic factor in a recent population study. We used a new DNA repair assay, the host-cell reactivation, in a clinic-based case-control study to test the hypothesis that reduced DNA repair is the underlying molecular mechanism for the development of sunlight-induced basal cell carcinoma. The peripheral lymphocytes from 88 patients with primary BCC and 135 cancer-free controls were tested for their capacity to repair ultraviolet light-induced DNA damage in a reporter gene, chloramphenicol acetyl transferase. All subjects were between the ages of 20 and 60 years and were frequency matched by age (+/- 5) and sex. Among those who reported frequent sunbathing, poor tanning ability, a history of multiple sunburns, exposure to chemicals, or multiple medical irradiations, the BCC patients had significantly lower DNA repair capacity than controls (p < 0.05). DNA repair capacity was also found substantially lower in the basal cell carcinoma patients who had red hair and light skin (type I). Compared to controls, basal cell carcinoma cases with selected risk factors had a relative decrease in DNA repair capacity of 10-28%. These findings provided evidence that reduced DNA repair capacity is one of the underlying molecular mechanisms for sunlight-induced skin carcinogenesis in the general population.