Population Of Similar Age Research Articles

Molar incisor hypomineralization in Hong Kong Chinese children

Most prevalence studies on molar incisor hypomineralization (MIH) were carried out in European countries, and data from the East-Asian populations were lacking. This study aimed to investigate the prevalence of MIH in Hong Kong Chinese children. Since 2006, charting of teeth with MIH was included into the routine dental examination in a school dental clinic. The dental records of grade 6 primary school children who attended annual check-up in this clinic in 2006 were subsequently reviewed retrospectively. The records were selected for this study if the charting indicated that the children were affected by MIH. A total of 2635 records were reviewed and 73 cases of MIH were identified. The prevalence of MIH in this group of children was 2.8%. Their mean age was 12, and the male-to-female ratio was 1 : 1.2. The mean decayed, missing, or filled permanent teeth value of those affected was 1.5, which was higher than that of the general Hong Kong Chinese children aged 12 years old (0.8). A total of 192 teeth were affected. The most commonly affected teeth were permanent maxillary first molars, followed by mandibular first molars and maxillary central incisors. Dental fillings and fissure sealants were found in 52 (38%) and 65 (47%) permanent first molars with hypomineralization, respectively. Medical histories were unremarkable in 60 children, whereas early childhood diseases were reported in 13 cases. The prevalence of MIH in the permanent dentition of Hong Kong Chinese children was 2.8%. Children with MIH showed higher caries experience in the permanent dentition than the general population of similar age.

Feasibility of a screening programme for lung cancer in former asbestos workers

Low-dose computed tomography (CT) has been found to detect more Stage IA lung cancer than chest x-ray. To investigate whether lung cancer screening with CT was effective and acceptable in former asbestos workers. CT scanning was carried out following the protocol previously described in the literature. A questionnaire was used to assess cumulative asbestos exposure. An economic analysis was also performed. Informed consent was obtained from all patients. A total of 1119 male asbestos workers (58% of invited) were examined, of whom 65% were smokers or ex-smokers. Mean age was 57.1 years with mean cumulative exposure to asbestos of 123 fibres/ml x years. Pleural plaques were found in 375 workers (32%), while 338 workers (29%) were included in the radiological follow-up, which led to 25 biopsies (13 of lung, 9 of pleura, 3 of both) and five screen-detected lung cancers (0.4%), one in Stage I. Incidence rate was 149 per 10(5), equal to that in the male general population of similar age. The expenses for diagnosis were 1014 and 244962 Euro per screened subject and screen-detected lung cancer case, respectively. Screening adherence and frequency of detection were low, while costs and radiation dose were high. In spite of a high cumulative asbestos exposure, lung cancer risk was not increased relative to the general population. The screening programme was not felt to be cost-effective from the perspective of the government as a third-party funding agency.

Analysis of LGI1 promoter sequence, PDYN and GABBR1 polymorphisms in sporadic and familial lateral temporal lobe epilepsy

Autosomal dominant lateral temporal epilepsy (ADTLE) is a genetically transmitted epileptic syndrome characterized by focal seizures with predominant auditory symptoms likely originating from the lateral region of the temporal lobe. Mutations in coding region or exon splice sites of the leucine-rich, glioma-inactivated 1 (LGI1) gene account for about 50% of ADLTE families. De novo LGI1 mutations of the same kind have also been found in about 2.5% of non-familial cases with idiopathic partial epilepsy with auditory features (IPEAF). In both conditions, mutations in the LGI1 promoter region have not been reported. We sequenced the minimal promoter region of LGI1 in the probands of 16 ADLTE families and in 104 sporadic IPEAF patients and no mutations clearly linked to the disease were found. However, two polymorphisms, -500G>A and -507G>A, with potential functional implications were identified and analysed in the cohort of sporadic IPEAF patients but their frequencies did not differ from those found in a control population of similar age, gender and geographic origin. We also analysed in our study population the GABA(B) receptor 1 c.1465G>A and the prodynorphin promoter 68-bp repeat polymorphisms, previously associated with temporal lobe epilepsy. None of these polymorphisms showed a significant association with IPEAF, whereas a tendency towards association with the prodynorphin low expression (L) alleles was found in the small group of ADLTE index cases, in agreement with previous studies suggesting that this polymorphism is a susceptibility factor in familial forms of temporal lobe epilepsy.

Asymptotic giant branch stars in the Phoenix dwarf galaxy

JHKs near-infrared photometry of stars in the Phoenix dwarf galaxy is presented and discussed. Combining these data with the optical photometry of Massey et al. allows a rather clean separation of field stars from Phoenix members. The discovery of a Mira variable (P = 425 days), which is almost certainly a carbon star, leads to an estimate of the distance modulus of 23.10+/-0.18 that is consistent with other estimates and indicates the existence of a significant population of age ~2 Gyr. The two carbon stars of Da Costa have M{bol} = -3.8 and are consistent with belonging to a population of similar age; some other possible members of such a population are identified. A Da Costa non-carbon star is Delta Ks~0.3 mag brighter than these two carbon stars. It may be an AGB star of the dominant old population. The nature of other stars lying close to it in the Ks,(J-Ks) diagram needs studying.

External beam radiation treatment for rectal cancer is associated with a decrease in subsequent prostate cancer diagnosis

External beam radiation therapy (EBRT) for rectal cancer unavoidably delivers significant radiation dose to the prostate gland. The effect of this incidental exposure on subsequent prostate cancer diagnosis was investigated using the Surveillance, Epidemiology, and End Results (SEER) cancer registry. Men diagnosed with localized or regional (L/R) rectal cancer from 1988-1997 and treated with EBRT and sphincter-sparing surgery (SSS) were identified. Men treated for L/R rectal cancer with SSS who did not receive EBRT, and men with L/R colon cancer who did not receive EBRT, were studied for comparison. Multiple Primary Standardized Incidence Ratios of observed to expected (O/E) cases of prostate cancer were calculated using SEER*Stat. In all, 1574 men with L/R rectal cancer treated with EBRT and SSS were identified. The median age at diagnosis was 64 and median survival was 76 months. Twenty were subsequently diagnosed with prostate cancer, a number significantly less than expected compared with the general population of similar age and race. The ratio of O/E cases was 0.28 (95% confidence interval [CI], 0.17, 0.43). In contrast, 3114 men diagnosed with rectal cancer undergoing SSS who were not treated with EBRT and 24,578 men diagnosed with colon cancer who were not treated with EBRT were subsequently diagnosed with prostate cancer at rates similar to the general population (O/E of 0.94 and 1.09). EBRT for L/R rectal cancer was associated with a 72% decrease in the frequency of subsequent prostate cancer diagnosis when compared with men of similar age and race. Possible mechanisms that may explain this observation are discussed.

Lower limb muscle strength and physical activity in healthy individuals approaching retirement

The purpose of this study was to examine knee extensor/flexor muscle strength and physical activity in healthy males and females approaching retirement. Peak torques of the knee extensor and knee flexor muscle groups were measured bilaterally in 95 individuals (mean age 59.4 years) using an isokinetic dynamometer. Isokinetic concentric contractions were performed at angular velocities of 1.05 and 3.14 rad · s−1. Physical activity, including household, leisure, and sporting activities, was assessed. The results show that the average peak torques exhibited were lower than previously reported in studies using the same methodology with different populations of similar age and body size. Over one-third of the participants were sedentary, with just 13% being active enough to obtain health benefits. The poor muscle strength and low physical activity of this self selecting group of healthy working adults were surprising, and potentially a cause for concern. The combination of retirement being a potential watershed for a decrease in physical activity and the known age-related decline in physical performance indicates that some of these participants are at risk of losing their functional independence fairly early in the retirement stage. We recommend the introduction of effective health promotion interventions for individuals approaching retirement, encouraging them to become more physically active.

Incidence and causes of death in HIV‐infected persons receiving highly active antiretroviral therapy compared with estimates for the general population of similar age and from the same geographical area

Since the introduction of highly active antiretroviral therapy (HAART), the incidence of death in HIV-infected patients has dramatically decreased, and causes of death other than those related to HIV infection have increased, although it is unclear how these parameters compare with those in the age-matched general population living in the same geographical region. Consecutive HIV-infected adults who were prescribed HAART in our hospital were prospectively followed from January 1997 to December 2004 or until death, loss to follow-up or discontinuation of HAART. Estimations of the annual incidence and causes of death in the general population of similar age in Catalonia per calendar year in the study period were obtained and compared with those in the HIV-infected cohort. There were 235 deaths among the 4471 patients on HAART (5%). The incidence of mortality decreased over time in HIV-infected patients (P<0.001; chi(2) test for trend), although it has remained approximately five times higher than that for the age-matched general population. AIDS-related events were the most common cause of death (n=95; 40%), although they significantly decreased over time (P<0.001; chi(2) test for trend), whereas liver diseases (P<0.001; chi(2) test for trend) and non-AIDS-defining infections (P=0.008; chi(2) test for trend) significantly increased over time. Infections in general (33 times higher), liver diseases (11 times higher) and non-Hodgkin lymphoma (5 times higher) were overrepresented as causes of death in the HIV-infected cohort compared with the age-matched general population. Non-AIDS-defining infectious diseases, liver diseases, and non-Hodgkin lymphoma represent specific targets for efforts to further decrease mortality in HIV-infected patients receiving HAART.

Quality of life in focal, segmental, and generalized dystonia

The objective of this study was to assess quality of life (QoL) in a community-based sample of people with various forms of dystonia and to identify the factors that predict QoL in dystonia. QoL was assessed using two generic questionnaires: the Medical Outcomes Study Short-Form 36 (SF36) and the EuroQol questionnaire. A host of demographic, clinical, and psychosocial variables were measured to identify the best predictors of QoL in dystonia. A comparison of EuroQol and SF36 scores with the norms for the general UK population of similar age showed that people with dystonia had scores indicative of worse QoL on all domains, particularly those related to physical and social functioning. The impairment of QoL was seen in all age groups and was similar for men and women. Compared to the focal dystonia group, participants with generalized dystonia scored significantly worse on all QoL measures. Participants who were unemployed also scored significantly worse. There was also a trend for younger and separated/divorced participants to score worse on QoL measures. A stepwise regression analysis revealed that functional disability, body concept, and depression were important predictors of QoL in dystonia. Dystonia influences various aspects of QoL, particularly those related to physical and social functioning. The impairment of QoL was greater for participants with generalized dystonia, those who were unemployed, younger, and separated/divorced. Functional disability, body concept, and depression were the best predictors of QoL in dystonia. Efforts to improve health care for people with dystonia should not only focus on management of the movement disorder but also consider modifying functional disability and negative body concept and depression that contribute to poor QoL in this disorder.

Parkinson's disease and working capacity

The purpose of the present study was to establish how Parkinson's disease (PD) affects working capacity. Altogether, 937 (70%) of 1,343 working-aged members of the Finnish Parkinson Association participated in a questionnaire study. The ages of the subjects were between 29 and 65 years, median 59.0 years; 508 (54%) were men. The median (quartile range) duration of PD symptoms was 7.3 (4.3-11.3) years, and the median self-estimated severity of the disease on the Hoehn & Yahr scale was 2. Only 150 of 937 subjects (16%) were still working: 112 (12%) full-time and 38 (4%) part-time. Among those 343 (37%) who had retired purely because of PD at a median age of 53.4 years, the median working time was 1.7 years after established diagnosis. In part-time work, PD patients had been able to continue for a median of 4.3 years. PD often leads to early retirement; compared with the general Finnish population of similar age, PD patients had retired on the average 6 years earlier. Young age, mild symptoms, and short duration of the disease as well as adjustments enabling easier employment were associated with the possibility to continue longer in the work force.

Depressive symptoms in the very old living alone: prevalence, incidence and risk factors

Living alone is one of many risk factors associated with depression. This project is nested within the ENABLE-AGE project designed to explore the relationship between housing environment and health in the very old living alone in their own homes. Our aim is to describe the prevalence, incidence and associated risk factors of clinically significant depressive symptoms in this population with particular emphasis on the role of the home environment. We conducted a one year follow up of 376 subjects aged between 80 and 90 years old. Data collected included variables concerned with housing, social circumstances, physical health and psychological well being. A prevalence rate of 21% and an annual incidence of 12.4% (Geriatric Depression Score of five or more) were found. Risk factors associated with prevalence depression include not living close to friends and family ((OR 2.540, CI; 1.442, 4.466), poor satisfaction with living accommodation (OR; 0.840, CI; 0.735, 0.961) and poor satisfaction with finances (OR; 0.841, CI; 0.735, 0.961). Subsequent development of clinically significant depressive symptoms was associated with base line increased scores in depression (OR; 1.68, CI; 1.206, 2.341). These results are consistent with findings in the general population of similar age with the exception of considerably higher prevalence and incidence rates. However, we were unable to demonstrate that housing related variables were significant risk factors in terms of incidence cases. Older people living alone are particularly vulnerable to depression and may benefit from targeted screening and development of appropriate care pathways.

Early investigation and treatment of obstructive sleep apnoea after acute stroke

Obstructive sleep apnoea (OSA) is an independent risk factor for hypertension, which is a major cause of stroke. The prevalence and associations of OSA in a cohort of stroke patients were studied. The safety and tolerability of early treatment with nasal continuous airways pressure (nCPAP) was also assessed. Consecutive subjects admitted with acute stroke were assessed clinically, radiologically and with scales assessing prior OSA risk, dysphagia and disability. Sleep studies were performed within the first few days of admission using a portable diagnostic system. Twenty-nine of 55 (53%) subjects had evidence of OSA, using an apnoea-hypopnoea index (AHI) of 10 or greater. The AHI was significantly associated with an index of prior OSA symptoms, but not with history of hypertension, degree of dysphagia, or type and severity of stroke. Use of a portable diagnostic system for detecting OSA in the acute stroke setting was well tolerated. OSA is common after acute stroke and exceeds rates seen in control populations of similar age (53% vs. 11%). Early treatment with nCPAP was effective and well tolerated.

Oxidized LDL and the Metabolic Syndrome

The metabolic syndrome is a common and complex disorder combining obesity, dyslipidemia, hypertension and insulin resistance. It is associated with a high cardiovascular risk that can only partially be explained by its components. There is evidence that low-grade inflammation and high oxidative stress add to this risk. Oxidized LDL, a marker of lipoprotein-associated oxidative stress, is an emerging cardiovascular risk factor. In this review, we demonstrate that the metabolic syndrome exacerbates oxidized LDL in a feedback loop. We introduce molecular mechanisms underlying this loop. Finally, we demonstrate that weight loss and statin treatment lower metabolic syndrome factors associated with a reduction of oxidized LDL. The current data warrant further investigation into the role of lifestyle and therapeutic interventions that inhibit tissue-associated oxidation of LDL in the prevention of the metabolic syndrome.

Near infrared imaging of the broad absorption line quasar BAL QSO 0134+3253

In this paper we present near infrared (NIR) imaging data of the host galaxy of the broad absorption line quasar (BALQ) at $z=2.169$, serendipitously found close to 3C 48 (Canalizo et al. 1998, AJ, 115, 890). The data were obtained with the ESO-VLT camera ISAAC during period 67. We find extended, rest-frame optical emission around the BALQ after subtracting a scaled stellar point spread function from the quasar nucleus in J , H , and $K{\rm s}$. The extended rest-frame optical emission can be interpreted as an approximately 2 Gyr old stellar population composing the host galaxy of the BALQ or a stellar population of similar age associated with an intermediate ($z=1.667$) absorption system spectroscopically identified by Canalizo et al. (1998). The rest-frame-UV emission on the other hand is dominated by a young, ~500 Myr old stellar population (Canalizo et al. 1998). The UV/optical colors resemble a mixture of the two populations, of which the young one accounts for about 80%. Assuming that the residual emission is located at the BALQ redshift, we find that the host galaxy has a resolved flux of about 10% of the BALQ flux. The physical scale is quite compact, typical for radio quiet QSOs or Lyman break galaxies at these redshifts, indicating that the systems are still in the process of forming.

Adolescent Girls with Polycystic Ovary Syndrome Have an Increased Risk of the Metabolic Syndrome Associated with Increasing Androgen Levels Independent of Obesity and Insulin Resistance

Adult women with polycystic ovary syndrome (PCOS) have an increased prevalence of the metabolic syndrome (MBS). The prevalence of MBS is also increasing in adolescents. Our objective was to test the hypothesis that the prevalence of MBS is increased in adolescent girls with PCOS compared with the general population and to determine the factors associated with an increased risk of the MBS in PCOS. We conducted a cross-sectional case-control study at academic medical centers with general clinical research centers. Participants included 49 adolescent girls with PCOS and 165 girls from the Third National Health and Nutrition Examination Survey (NHANES III) adolescent population of similar age and ethnic background. We assessed the prevalence of MBS according to currently proposed adolescent MBS criteria. Thirty-seven percent of adolescent girls with PCOS had MBS compared with 5% of NHANES III girls (P < 0.0001). None of the girls of normal body mass index (BMI) had MBS, whereas 11% of overweight and 63% of obese girls with PCOS had MBS compared with 0 and 32% of NHANES III girls, respectively. Girls with PCOS were 4.5 times more likely to have MBS than age-matched NHANES III girls after adjusting for BMI (odds ratio, 4.5; 95% confidence interval, 1.1-17.7; P = 0.03). The odds of having the MBS were 3.8 times higher for every quartile increase in bioavailable testosterone in girls with PCOS after adjusting for BMI and insulin resistance (odds ratio, 3.8; 95% confidence interval, 1.4-10.2; P = 0.008). Adolescent girls with PCOS have a higher prevalence of MBS than the general adolescent population. Hyperandrogenemia is a risk factor for MBS independent of obesity and insulin resistance.

The Buffalo Cardio-Metabolic Occupational Police Stress (BCOPS) Pilot Study: Methods and Participant Characteristics

The Buffalo Cardio-Metabolic Occupational Police Stress (BCOPS) study is one of the first population-based studies to integrate psychological, physiological, and subclinical measures of stress, disease, and mental dysfunction. This pilot study was undertaken to establish a methodology and descriptive results for a larger police study. A stratified sample of 100 officers was randomly selected from the Buffalo, NY Police Department. Salivary cortisol served as a stress biomarker. Flow mediated dilation (FMD) and carotid intima-media thickness (IMT) were performed with ultrasound. Dual Energy X-Ray Absorptiometry (DEXA) and anthropometric measures assessed body composition. Self-report measures of depression and posttraumatic stress disorder (PTSD) were obtained. Recruitment attained for the study was 100%. Seventy-five percent showed a cortisol increase upon awakening, 90% a negative diurnal slope, and 77% an increased cortisol response after a high protein lunch challenge. Dexamethasone suppression was evident. FMD showed an increase in mean brachial artery diameter of 3.2% in men and 3.9% in women, and mean IMT was lower (male=0.67 mm; female=0.62 mm) compared to populations of similar age. For males, the mean body-mass index (BMI) was 29.8 kg/m2 and total body fat 23.4%. For females, the mean BMI was 26.7 kg/m2 and total body fat 31.5%. For all officers, 16% met criteria for depression; 36% reported elevated PTSD symptoms. Compared to populations of similar age, police officers had slightly lower FMD, lower carotid IMT, elevated BMI, and higher reported rates of depression and PTSD. Standardized physiological and psychological data collection and descriptive results confirmed that the methodology of the study is feasible in a working police population.

Long-Term Persistence of Disability Following Severe Lower-Limb Trauma&lt;sbt aid="1025711"&gt;Results of a Seven-Year Follow-up&lt;/sbt&gt;

A recent study demonstrated that patients treated with amputation and those treated with reconstruction had comparable functional outcomes at two years following limb-threatening trauma. The present study was designed to determine whether those outcomes improved after two years, and whether differences according to the type of treatment emerged. Three hundred and ninety-seven patients who had undergone amputation or reconstruction of the lower extremity were interviewed by telephone at an average of eighty-four months after the injury. Functional outcomes were assessed with use of the physical and psychosocial subscores of the Sickness Impact Profile (SIP) and were compared with similar scores obtained at twenty-four months. On the average, physical and psychosocial functioning deteriorated between twenty-four and eighty-four months after the injury. At eighty-four months, one-half of the patients had a physical SIP subscore of > or = 10 points, which is indicative of substantial disability, and only 34.5% had a score typical of a general population of similar age and gender. There were few significant differences in the outcomes according to the type of treatment, with two exceptions. Compared with patients treated with reconstruction for a tibial shaft fracture, those with only a severe soft-tissue injury of the leg were 3.1 times more likely to have a physical SIP subscore of 5 points (p < 0.05) and those treated with a through-the-knee amputation were 11.5 times more likely to have a physical subscore of 5 points (p < 0.05). There were no significant differences in the psychosocial outcomes according to treatment group. Patient characteristics that were significantly associated with poorer outcomes included older age, female gender, nonwhite race, lower education level, living in a poor household, current or previous smoking, low self-efficacy, poor self-reported health status before the injury, and involvement with the legal system in an effort to obtain disability payments. Except for age, predictors of poor outcome were similar at twenty-four and eighty-four months after the injury. The results confirm previous conclusions that reconstruction for the treatment of injuries below the distal part of the femur typically results in functional outcomes equivalent to those of amputation. Regardless of the treatment option, however, long-term functional outcomes are poor. Priority should be given to efforts to improve post-acute-care services that address secondary conditions that compromise optimal recovery.

EXTRINSIC FACTORS SIGNIFICANTLY AFFECT PATTERNS OF DISEASE IN FREE-RANGING AND CAPTIVE CHEETAH (ACINONYX JUBATUS) POPULATIONS

The cheetah (Acinonyx jubatus) has been considered a paradigm for disease vulnerability due to loss of genetic diversity. This species monomorphism has been suspected to be the basis for their general poor health and dwindling populations in captivity. North American and South African captive populations have high prevalences of hepatic veno-occlusive disease, glomerulosclerosis, gastritis, and systemic amyloidosis, diseases that are rare in other species. Unusually severe inflammatory reactions to common infectious agents have also been documented in captive cheetahs. The current study compared disease prevalences in free-ranging Namibian cheetahs with those in two captive populations of similar ages. The occurrence of diseases in the free-ranging population was determined from 49 necropsies and 27 gastric biopsies obtained between 1986 and 2003 and compared with prevalences in 147 North American and 80 South African captive cheetahs. Except for two cheetahs, the free-ranging population was in robust health with only mild lesions present, in contrast with significantly higher prevalences in the captive populations. Despite widespread heavy Helicobacter colonization in wild cheetahs, only 3% of the free-ranging population had moderate to severe gastritis, in contrast with 64% of captive cheetahs. No severe inflammatory reactions to viral infections were detected in the free-ranging animals. Because free-ranging Namibian cheetahs are as genetically impoverished as captive cheetahs, these findings caution against attributing loss of fitness solely to genetic factors and attest to the fundamental importance of extrinsic factors in wildlife health.

Cannabis Use and Schizophrenia

Back to table of contents Previous article Next article Letter to the EditorFull AccessCannabis Use and SchizophreniaDARRYL WADE, M.A., DARRYL WADESearch for more papers by this author, M.A., Melbourne, Vic., AustraliaPublished Online:1 Feb 2005https://doi.org/10.1176/appi.ajp.162.2.401AboutSectionsPDF/EPUB ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InEmail To the Editor: The study by Natalie D. Veen, M.D., and colleagues (1) found an association between cannabis use and younger age at onset of schizophrenia in male patients in a first-contact incidence study and recommended additional studies to examine this possible causal relationship. The authors considered three potential explanations for the association. Two of these explanations were as follows: cannabis use can “bring forward” the onset of a psychotic disorder in individuals who would have developed the disorder whether they had used cannabis or not, and cannabis use can cause schizophrenia in at least some individuals who would not have developed schizophrenia had they not used cannabis. However, as Dr. Veen and colleagues noted, there is scant epidemiological evidence to support these potential mechanisms (2).A third explanation was that cannabis has no influence on age at onset and that the association between the two variables is simply because younger patients are more likely to use cannabis. This would seem to be a plausible explanation for two reasons. First, younger individuals at first contact would be expected to have a younger age at onset of a psychotic episode than older individuals. Second, younger age (and male gender) is a reliable demographic predictor of substance misuse in individuals with psychotic disorders as well as the general community (3). As a result, it should not be surprising that patients with a comparatively younger age at onset are at increased risk for the use of cannabis and other substances. Dr. Veen and colleagues argued that this explanation was not supported by their finding of a higher rate of cannabis use in the incidence cohort compared to members of the general population of similar age. However, this is not relevant to the fact that younger age is a robust risk factor for substance use in both clinical and community populations. Rather, it points to the need to better understand the high prevalence of substance misuse found in psychotic disorders. For example, the higher prevalence of cannabis use in the incidence cohort relative to the general population is likely to be partly due to the high proportion of male patients recruited into the study.This appears to be a promising study that will inform our understanding of the onset and early course of psychotic disorders, and I hope that this comment will be a positive contribution to the interpretation of its findings.

Cannabis Use and Schizophrenia

TO THE EDITOR: The study by Natalie D. Veen, M.D., and colleagues (1) found an association between cannabis use and younger age at onset of schizophrenia in male patients in a first-contact incidence study and recommended additional studies to examine this possible causal relationship. The authors considered three potential explanations for the association. Two of these explanations were as follows: cannabis use can “bring forward” the onset of a psychotic disorder in individuals who would have developed the disorder whether they had used cannabis or not, and cannabis use can cause schizophrenia in at least some individuals who would not have developed schizophrenia had they not used cannabis. However, as Dr. Veen and colleagues noted, there is scant epidemiological evidence to support these potential mechanisms (2). A third explanation was that cannabis has no influence on age at onset and that the association between the two variables is simply because younger patients are more likely to use cannabis. This would seem to be a plausible explanation for two reasons. First, younger individuals at first contact would be expected to have a younger age at onset of a psychotic episode than older individuals. Second, younger age (and male gender) is a reliable demographic predictor of substance misuse in individuals with psychotic disorders as well as the general community (3). As a result, it should not be surprising that patients with a comparatively younger age at onset are at increased risk for the use of cannabis and other substances. Dr. Veen and colleagues argued that this explanation was not supported by their finding of a higher rate of cannabis use in the incidence cohort compared to members of the general population of similar age. However, this is not relevant to the fact that younger age is a robust risk factor for substance use in both clinical and community populations. Rather, it points to the need to better understand the high prevalence of substance misuse found in psychotic disorders. For example, the higher prevalence of cannabis use in the incidence cohort relative to the general population is likely to be partly due to the high proportion of male patients recruited into the study. This appears to be a promising study that will inform our understanding of the onset and early course of psychotic disorders, and I hope that this comment will be a positive contribution to the interpretation of its findings.

Mid term analysis of safety and quality of life after the laparoscopic repair of paraesophageal hiatal hernia.

Initial experience with the laparoscopic repair of paraesophageal and type III mixed hiatal hernias showed that it is safe and feasible, with excellent immediate and short-term results. However, after a longer follow-up, a recurrence rate of < or =40% has been demonstrated. Data related to the outcome of paraesophageal hernia repair and the recurrence rate are still lacking. Quality-of-life scores may offer a better means of assessing the impact of surgical treatment on the overall health status of patients. Therefore, we performed prospective evaluation of anatomic and/or symptomatic recurrences after paraesophageal or large hiatal hernia repair. In addition, we investigated the correlation between recurrence and the patient's quality of life. All patients after who had undergone repair of paraesophageal of mixed hiatal hernia were identified prospectively from a database consisting of all patients who had had laparoscopic operations for gastroesophageal pathology at our hospital between February 1998 and December 2002. The preoperative symptoms were taken from patients' clinical files. In March 2003, all patients with > or =6 months of follow-up had a barium swallow and were examined for radiological and clinical signs of recurrence. Thereafter, the patients' quality of life after surgery was evaluated using three standard questionnaires (Short Form 36 [SF-36], Glasgow Dyspepsia Severity Score [GDSS], and Gastrointestinal Quality of Life Index [GIQLI]. During the study period, 46 patients had been operated on. The mean age was 63 years (range, 28-93). Thirty seven of them had a follow-up of > or =6 months. Eight patients (21%) had postoperative gastrointestinal symptoms. Barium swallow was performed in 30 patients (81%) and showed a recurrence in six of them (20%). According to SF-36 and GDSS, the patients' postoperative quality of life reached normal values and did not differ significantly from the standard values for the Spanish population of similar age and with similar comorbidities. Successfully operated patients reached a GIQLI value comparable to the standard population. However, symptomatic patients had significantly lower GIQLI scores than the asymptomatic or the Rx-recurrent group. The laparoscopic treatment of large paraesophageal and mixed hiatal hernias is not only feasible and safe but also offers a good quality of life on a midterm basis. However, the anatomic and functional recurrence rate is high. The next step is to identify the subset of patients who are at risk of failure and to establish technical alternatives that would ensure the durability of the repair.