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PubMed2002

Pertussis infection in childhood and subsequent type 1 diabetes mellitus.

AIMS: Pertussis has been implicated but not proven as a risk for Type 1 diabetes mellitus (DM). Previous studies have investigated paediatric, but not adult-onset Type 1 DM. We investigated association of pertussis exposures and Type 1 DM with follow-up into adulthood. METHODS: Longitudinal analysis of 16 820 members (100 with Type 1 DM) of two nationally representative British birth cohorts (the 1970 British Cohort Study (BCS70) and the National Child Development Study (NCDS)) followed from birth to ages 30 years (BCS70) and 42 years (NCDS). Cox regression analysis with age of onset for Type 1 DM as the dependent variable investigated relationships with pertussis infection and immunization, modelled as time-dependent co-variates. Simultaneous adjustment was made for Wild measles, mumps and chickenpox infections; tetanus and smallpox immunizations; sex, parental social class and cohort. The potential confounding factors were modelled as fixed co-variates. RESULTS: Cox regression analysis produced adjusted odds ratios (ORs) (with 95% confidence intervals (CIs)) of 2.21 (1.35-3.59) and 0.73 (0.49-1.05) for Type 1 DM (with onset at any age) associated with pertussis infections and immunization (trend over number of vaccinations), respectively. Adjusted ORs from Cox regression for Type 1 DM with onset after age 10 years are 2.59 (1.56-4.30) for pertussis infection and 0.63 (0.42-0.94) for pertussis immunization. None of the other infections or immunizations are notably associated with Type 1 DM. CONCLUSIONS: Some pertussis infections may be a risk for Type 1 DM and immunization may confer protection. Further research should consider delayed Type 1 DM following pertussis exposures.

Adolescent↗
PubMed1988

Fiber intake, age, and other coronary risk factors in men of the Baltimore Longitudinal Study (1959-1975).

Fiber intake was estimated by 7-day diet record in community-dwelling men of the Baltimore Longitudinal Study of Aging. The mean intake of 845 men (age 20-103) was 3.82 +/- 0.03 g crude fiber/day which corresponds to approximately 15 g/day of dietary fiber. Fiber intake increased across the age span (slope = +0.022 +/- 0.003 g/yr, p less than .01). Longitudinal analysis of 380 men, each of whom provided 3-8 diet records over an average period of 8 yr, indicated that the increase in fiber intake occurred in each age group and was not the result of differential survival. Fiber intake was negatively correlated with body mass index. After clinical screening to eliminate variables which could independently influence coronary risk factors, multiple regression analyses including age and body mass index were conducted to examine the effect of fiber (adjusted for total calorie intake) on blood pressure, blood lipids, and glucose tolerance. For systolic and diastolic blood pressure, triglyceride, and fasting plasma glucose, higher fiber intake was associated with lower levels of the risk factors (p less than .05).

Adult↗
PubMed2006

Multimodal evoked potentials to assess the evolution of multiple sclerosis: a longitudinal study.

BACKGROUND: Evoked potentials are used in the functional assessment of sensory and motor pathways. Their usefulness in monitoring the evolution of multiple sclerosis has not been fully clarified. OBJECTIVE: The aim of this longitudinal study was to examine the usefulness of multimodal evoked potential in predicting paraclinical outcomes of disease severity and as a prognostic marker in multiple sclerosis. METHODS: Eighty four patients with clinically definite multiple sclerosis underwent Expanded Disability Status Scale (EDSS) and functional system scoring at study entry and after a mean (standard deviation) follow-up of 30.5 (11.7) months. Sensory and motor evoked potentials were obtained in all patients at study entry and at follow-up in 64 of them, and quantified according to a conventional score. RESULTS: Cross-sectionally, the severity of each evoked potential score significantly correlated with the corresponding functional system (0.32 < R < 0.60, p < 0.01, for all but follow-up visual evoked potential) and with EDSS (0.34 < R < 0.61; p < 0.001 for all but brain stem evoked potential). EDSS significantly correlated with global evoked potential score severity (baseline R = 0.60, follow-up R = 0.46, p < 0.001). Using longitudinal analysis, only changes in somatosensory evoked potential scores were significantly correlated with changes of sensory functional system (R = 0.34, p = 0.006). However, patients with multiple sclerosis with disability progression at follow-up had more severe baseline evoked potential scores than patients who remained stable. Patients with severe baseline global evoked potential score (higher than the median value) had a risk of 72.5% to progress on disability at follow-up, whereas patients with multiple sclerosis with lower scores had a risk of only 36.3%. CONCLUSIONS: These results suggest that evoked potential is a good marker of the severity of nervous damage in multiple sclerosis and may have a predictive value regarding the evolution of disability.

Adult↗
PubMed1993

Longitudinal experience with botulinum toxin injections for treatment of blepharospasm and cervical dystonia.

We performed a longitudinal analysis of the effects of repeat botulinum toxin (BTX) injections in 42 patients with blepharospasm (BL) and 115 patients with cervical dystonia (CD) who received BTX injections between 1984 and 1992 in at least five separate treatment sessions. Although the BL patients were significantly older (59.8 years) than the CD patients (50.6 years; p < 0.001), there were no other demographic differences between the two groups. While the total dose per treatment session and the peak effect rating remained the same, the duration of benefit increased and the number of complications decreased during the course of treatment. We concluded that chronic treatment with BTX in patients with BL and CD is not associated with any decline in benefit, and that efficacy may improve slightly with repeat treatments.

Adolescent↗
PubMed2006

The nutritional status of children with cystic fibrosis.

The importance of nutritional intervention for children with cystic fibrosis (CF) is well recognised. It would be expected that the increase in knowledge over the past decade would be reflected in improvements in nutritional status for the CF paediatric population. The aim of the present paper was to evaluate the nutritional status of children with CF, cross-sectionally and longitudinally. Body cell mass adjusted for gender and size (BCM/Htp) was measured in sixty-four children with CF to represent nutritional status and expressed as a Z-score. The cross-sectional results showed a mean BCM/Htp Z-score of 0.54 (sd 1.21), with males having a slightly higher Z-score than females but with a larger variation. At the initial measurement, only one female and one male were considered sub-optimally nourished. The longitudinal analysis after 2 years showed that the mean population had a significantly decreased BCM/Htp Z-score; however, when each gender was analysed separately, this decrease was significant only in the males. At the final measurement, only two females and three males were considered sub-optimally nourished. It is evident from our results that children with CF are well nourished, with only a small percentage considered malnourished. It appears that nutritional status decreases with age, with this decline being more evident in males. These results signify that although children with CF are better nourished with current treatment support, intervention needs to continue throughout a CF patient's life to counteract the changes that occur with age.

Body Height↗
PubMed1994

Detection of herpesvirus type 6 by polymerase chain reaction in blood donors: random tests and prospective longitudinal studies.

In order to evaluate the prevalence of HHV-6 in blood donors, we examined 112 persons by polymerase chain reaction (PCR) and ELISA. HHV-6 antibodies could be detected in 107/111 (96.4%) of the donors. The median ELISA antibody level was 0.451 (range 0.056-0.914). 14 individuals (12.5%) were PCR positive in either oral lavage fluid, urine or buffy coat. Six persons (5.4%) were PCR positive in buffy coat samples. The prospective longitudinal analysis of 11 donors for periods between 7 and 13 weeks revealed that 4/6 persons who were initially PCR negative had positive tests in 9/63 weeks studied. Two persons were consistently PCR positive over the whole observation period of 12 and 13 weeks. HHV-6 variants could be determined in 14 persons as variant A in nine and variant B in five cases. These observations emphasize the high prevalence of HHV-6 and suggest that some blood donors carry detectable concentrations of the virus and therefore may be a source for transmission of HHV-6. The finding of positive PCR in antibody negative individuals suggests that antibody determination may not be sufficient to identify potentially infectious persons.

Antibodies, Viral↗
PubMedDate not supplied

Health indices as predictors of cognition among older African Americans: MacArthur studies of successful aging.

Using cross-sectional and longitudinal data from the MacArthur Successful Aging Study, this paper examines associations between cognition and indices of health in 224 elderly African Americans 70 to 79 years of age at initial interview. The results indicated that greater average peak expiratory flow was predictive of better cognitive performance at the first interview. One longitudinal analysis showed that gender was the only significant predictor of change (change as a continuous variable) with women tending to slightly improve their cognitive performance over time. When change was treated as a dichotomous variable (e.g., a decline of 6 or more points), lower levels of average peak expiratory flow and education were predictive of decline, and positive self-ratings of current health and changes in health in the past year were important factors in the improvement of cognitive performance. The results indicate that, in addition to education, health is an important predictor of the status and course of cognitive functioning in older African Americans.

Black or African American↗
PubMed2002

The autoimmune response to chromatin antigens in systemic lupus erythematosus: autoantibodies against histone H1 are a highly specific marker for SLE associated with increased disease activity.

This study investigates specificity, sensitivity and concomitant presence of antibodies against histone H1 (H1), nucleosomes (NUC), chromatin (CHR) and dsDNA in patients with systemic lupus erythematosus (SLE), analyses their association with SLE disease activity and characterizes the immunodominant epitope reactivity of anti-H1 antibodies and its relation to SLE disease activity. In a cross-sectional study 394 sera of patients with various rheumatic diseases and healthy subjects were analysed by ELISA for antibodies against H1, NUC, CHR and dsDNA. In addition, a longitudinal analysis was performed that included 121 sequential serum samples derived from 16 SLE patients to assess the relation of these antibodies as well as antibodies to histone H2B to SLE disease activity. To assess epitope reactivity of anti-H1 antibodies overlapping synthetic peptides covering the entire H1 sequence were used. Anti-H1 antibodies yielded a sensitivity of approximately 45% and a specificity of over 98% for SLE, which was comparable to that found for anti-dsDNA antibodies. Anti-CHR and anti-NUC antibodies were of similar sensitivity but slightly (anti-CHR) or considerably (anti-NUC) less specific for SLE (95 and 85%, respectively). The sequential analysis revealed a strong correlation of anti-H1 antibodies with SLE disease activity that was better than the correlation of anti-dsDNA and anti-NUC antibodies, while only weak correlation was found for anti-CHR and anti-H2B antibodies. The immunodominant epitope for anti-HI was localised between amino acids 204 and 218 (pp204-218) and immune reactivity to this epitope also correlated with disease activity. Anti-H1 is a highly specific marker for SLE with a diagnostic value comparable to anti-dsDNA. A positive testing for anti-H1 indicates increased disease activity, as does the appearance of antibodies to its immunodominant epitope pp204-218.

Antibodies, Antinuclear↗
PubMed1993

A comparison of the recovery termination rates of disabled-worker beneficiaries entitled in 1972 and 1985.

This article reports on the final phase of a longitudinal analysis of two cohorts of Disability Insurance (DI) beneficiaries. The analysis shows that changes in DI program provisions and demographic shifts in the beneficiary population have considerably affected standard recovery termination rates. Several covariates were also found to affect the rates, particularly age and education. Overall, the 1985 cohort has a lower standard recovery termination tendency during the first few years of entitlement. After an attempt was made to define a recovery event for the 1985 cohort to make it comparable to the 1972 cohort, it was found that the termination rate for the 1985 cohort was still lower than the termination rate for the 1972 cohort. These findings suggest that there will be fewer recoveries for beneficiaries who entered the DI program in the late 1980's than for those who came on the rolls earlier.

Adolescent↗
PubMed1993

The influence of health on family contacts and family feelings in advanced old age: a longitudinal study.

This study provides a longitudinal analysis of the influences of health, age, gender, and socioeconomic status on family contacts and family feelings in a sample of 62 members of the Berkeley Older Generation Study. Stability in family contacts and in family feelings was observed over 14 years of advanced old age. Of the four predictor variables, health and socioeconomic status accounted for the largest proportion of observed variance. Contrary to our hypotheses, study participants in better health had greater amounts of contact with family than did those in poorer health. The former also had more feelings of closeness to family members, a finding that may reflect greater possibilities for reciprocity between elders in good health and their family members.

Activities of Daily Living↗
PubMed2001

A longitudinal study of the relationship between levels of depression among persons with Alzheimer's disease and levels of depression among their family caregivers.

The purpose of this study was to examine the effects, over time, of depressive symptoms in persons with Alzheimer's disease on depression in their family caregivers. In a sample of 353 patients and caregivers, multilevel longitudinal analysis was used to accommodate an observational design in which the number of observation points and the intervals between points varied across caregivers. The rate of change (increase) in caregiver depression was predicted by the rate of change (increase) in patient depressive symptoms and by increase in patient dependency in instrumental activities of daily living (ADLs). Acceleration of the increase in caregiver depression was predicted by acceleration in patient dependency in instrumental and basic ADLs but not by acceleration in patient depressive symptoms. These findings indicate the importance of measuring the rate and acceleration of change in patient characteristics in order to understand caregiver depression. They also support early interventions for caregivers.

Activities of Daily Living↗
PubMed2001

A 15-year physical activity pattern is positively related to aerobic fitness in young males and females (13-27 years).

The purpose of this paper is to test the hypothesis that daily physical activity over a period of 15 years has been beneficial to aerobic fitness in young male and female participants (13-27 years) in the Amsterdam Growth and Health Longitudinal Study. Only subjects with the maximal data of six sets of measurements were included (83 male and 98 female participants). Daily physical activity was assessed using a standardized interview on activity and expressed as a weighted activity score. Aerobic fitness was assessed using a maximal running test on a treadmill and measuring the maximal oxygen uptake (VO2max) and the maximal slope of the track (Smax). To assess the longitudinal relationship between daily physical activity and aerobic fitness a real longitudinal analysis was carried out with generalized estimating equations, adjusting for differences in initial aerobic fitness at age 13, and for other lifestyle (dietary intake, smoking and alcohol consumption) and biological parameters (biological age, body fat, blood pressure and concentration of serum cholesterol). A significant relationship (P < 0.01) was observed between daily physical activity and both VO2max and Smax. It can be concluded that the development of aerobic fitness between the age of 13 and 27 years is independently and positively related to daily physical activity in this group of male and female participants in the study. The functional implications, however, are small: a relatively high increase in the weighted physical activity score of 30% over a period of 15 years results in a 2%-5% increase in aerobic fitness.

Adolescent↗
PubMed2005

Longitudinal patterns of methamphetamine, popper (amyl nitrite), and cocaine use and high-risk sexual behavior among a cohort of san francisco men who have sex with men.

Most prior studies examining drug use among men who have sex with men (MSM) have been cross-sectional or retrospective and have not determined whether periods of increased drug use are associated with high-risk sexual behavior at the individual level. In this article, we describe patterns of use of methamphetamines, poppers, and sniffed cocaine and sexual risk behavior among 736 San Francisco MSM enrolled in the EXPLORE study and followed for up to 48 months. In longitudinal analysis, use of methamphetamines, poppers, and sniffed cocaine declined during follow-up. However, compared with older participants, younger participants were more likely to increase their drug use over time. Results of conditional logistic regression demonstrated that high-risk sexual behavior was more common during reporting periods characterized by increased methamphetamine, poppers, or sniffed cocaine use. This within-person analysis found that compared with periods of no drug use, periods of both light drug use (less than weekly use of drugs) and heavier drug use (at least weekly use of at least one drug) were significantly associated with increased risk of engaging in unprotected anal sex with an HIV-positive or unknown-status partner. These results suggest that even intermittent, recreational use of these drugs may lead to high-risk sexual behavior, and that, to reduce and prevent risks of HIV, no level of use of these drugs should be considered "safe." HIV prevention interventions should target MSM who report either light or heavy use of methamphetamines, poppers, and sniffed cocaine.

Adolescent↗
PubMed1998

Management and control of asthma as assessed by actual/best function and corticosteroid use 1980-1993/4.

This study aimed to determine whether the changes in practice in the management of asthma since the early 1980s have improved standards (as assessed by higher actual/best function) and reduced the need for oral corticosteroids. All asthmatic outpatients were reviewed in 1980, 1983, 1988/89 and 1993/94. Therapeutic step, defined by suppressive medication alone, actual and best peak expiratory flow (PEF) were recorded. Cohorts from 1980, 1983 and 1988/89 were identified in whom best function was established on all subsequent occasions. Changes in practice demonstrated by cross-sectional review of all subjects were interpreted with the aid of longitudinal analysis of the cohorts. Attendance increased from 463 in 1980 to 772 in 1993/94. Between 1983 and 1993/94, the proportion maintained on inhaled corticosteroids increased from 49 to 84% with increased use of higher doses. Mean actual/best PEF rose from 80 to 87%, improving at each therapeutic step. The proportion needing rescue oral corticosteroids fell from 47 to 35% and maintenance oral corticosteroids from 20 to 9%. In the cohorts, there was a similar reduction in use of rescue corticosteroids, but not of maintenance oral corticosteroids. The study confirmed an increase in the use and dose of inhaled corticosteroids, and a better outcome at all treatment steps. The fall in the proportion of subjects dependent on oral corticosteroids was due to attrition, rather than weaning in later years.

Administration, Inhalation↗
PubMed2006

A population-based and longitudinal study of sexual behavior and multidrug-resistant HIV among patients in clinical care.

BACKGROUND: Population-based and longitudinal information regarding sexual risk behavior among patients with multidrug resistant (MDR) HIV and their sexual partners is of great public health and clinical importance. OBJECTIVE: To characterize the HIV sexual risk behaviors of patients with and without drug-resistant HIV in the clinical care setting over time. MEASUREMENTS: 393 HIV-positive patients completed questionnaires of self-reported sexual risk behaviors at approximate 6-month intervals extending over 24 months. HIV viral load and genotypic drug resistance obtained during the same time points were matched to the behavioral data. Multidrug resistance was defined as having resistance to 2 or 3 antiretroviral (ARV) drug classes. RESULTS: In serial cross-sectional analyses, 393 patients (44% female and 79% heterosexual) contributed 919 matched behavioral and virologic results over the 24 months of data collection. Of these, 250 patients (64%) reported having sex during at least 1 survey period resulting in greater than 10,000 sexual events with more than 1000 partners. Unprotected sexual behavior was reported by 45% of sexually active patients, resulting in 34% of all sex events that exposed 29% of all partners. Of these patients with unprotected sexual events, 31% had HIV drug resistance--11.6% with resistance to 2 classes of ARVs (2-class), and 1.8% with 3-class ARV resistance at the time of a sexual risk event. Close to 1000 or 28% of all unprotected sexual events involved resistant strains (11% of these with resistance to 2 classes and 0.2% with 3-class resistance, exposing 20% of unprotected sexual partners to resistant HIV (8% to 2-class and 0.6% to 3-class resistance). In longitudinal analysis among the 78 patients who reported a cumulative total of 12 months of sexual history and had resistance testing, 38% reported engaging in unprotected sexual behavior. There was substantial and complex variation in the distribution of unprotected sexual events and in the detection of resistance over time. CONCLUSION: In this study of HIV sexual risk and resistance over time among HIV-infected patients in clinical care, a substantial proportion engaged in unprotected sex and had drug-resistant HIV, frequently exposing partners to 1- or 2-class resistant HIV strains. However, relatively few exposures involved 3-class resistance. The dynamics of sexual risk behavior and HIV drug resistance are complex and vary over time and urgently require both general and targeted interventions to reduce transmission of resistant HIV.

Adult↗
PubMed1996

Longitudinal study of dental development in chimpanzees of known chronological age: implications for understanding the age at death of Plio-Pleistocene hominids.

Reconstruction of life history variables of fossil hominids on the basis of dental development requires understanding of and comparison with the pattern and timing of dental development among both living humans and pongids. Whether dental development among living apes or humans provides a better model for comparison with that of Plio-Pleistocene hominids of the genus Australopithecus remains a contentious point. This paper presents new data on chimpanzees documenting developmental differences in the dentitions of modern humans and apes and discusses their significance in light of recent controversies over the human or pongid nature of australopithecine dental development. Longitudinal analysis of 299 lateral head radiographs from 33 lab-reared chimpanzees (Pan troglodytes) of known chronological age allows estimation of means and standard deviations for the age at first appearance of 8 developmental stages in the mandibular molar dentition. Results are compared with published studies of dental development among apes and with published standards for humans. Chimpanzees are distinctly different from humans in two important aspects of dental development. Relative to humans, chimpanzees show advanced molar development vis a vis anterior tooth development, and chimpanzees are characterized by temporal overlap in the calcification of adjacent molar crowns, while humans show moderate to long temporal gaps between the calcification of adjacent molar crowns. In combination with recent work on enamel incremental markers and CAT scans of developing dentitions of Plio-Pleistocene hominids, this evidence supports an interpretation of a rapid, essentially "apelike" ontogeny among australopithecines.

Aging↗
PubMed2006

Uveitis in the elderly: epidemiological data from the National Long-term Care Survey Medicare Cohort.

PURPOSE: There is a paucity of population-based data on the epidemiology of uveitis in the elderly. In the past 40 years, only 2 U.S. population-based studies have examined the epidemiology of uveitis. The conclusions of these studies on the burden of uveitis in the elderly differ greatly. In this analysis, we use Medicare claims data to define the population-based incidence and prevalence of uveitis in the United States elderly population. DESIGN: Cohort study. PARTICIPANTS: A cohort of 21644 Medicare beneficiaries drawn for the National Long-term Care Survey, a random sample of U.S. adults 65 years and older, was followed up from 1991 through 1999. METHODS: The International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis codes specific to uveitis were queried. To decrease the inclusion of uveitis caused by surgery, diagnoses occurring within 3 months of intraocular surgery were excluded. The incidence and prevalence of uveitis by anatomic location was calculated for each year in the study. MAIN OUTCOME MEASURES: The onset of uveitis during a given year and its presence in subsequent years. RESULTS: The cumulative yearly incidence of uveitis ranged from 302/100000 to 424/100000 persons per year and averaged 340.9/100000 persons per year. Anterior uveitis was the most common form of uveitis in this population, with a mean incidence of 243.6 cases per 100000 persons per year. The incidence of posterior uveitis averaged 76.6/100000 and the incidence of panuveitis/endophthalmitis averaged 41.7/100000. Only 2 cases of intermediate uveitis occurred during the study period. The cumulative prevalence of uveitis doubled from 511/100000 in 1991 to 1231/100000 in 1999, with anterior uveitis accounting for most prevalent cases in every year. CONCLUSIONS: The burden of uveitis in the elderly is substantial and is higher than previously thought. Longitudinal analysis of Medicare claims data may provide a useful tool for monitoring uncommon diseases, such as uveitis, in the elderly population.

Aged↗
PubMed2000

Longitudinal survey of lymphocyte subpopulations in the first year of life.

Age-matched reference values for lymphocyte subpopulations are generally obtained via cross-sectional studies, whereas patients are followed longitudinally. We performed a detailed longitudinal analysis of the changes in lymphocyte subpopulations in a group of 11 healthy infants followed from birth up to 1 y of age, with special attention for early developmental markers, markers of maturation, and markers of activation. We found that T and B lymphocytes increased at 1 and 6 wk of age, respectively. In contrast, NK cells showed a sharp decline directly after birth, suggesting that they are more important during pregnancy than thereafter. CD45RA+--mainly CD4+--naive T lymphocytes were high at birth, and increased further during the first year of life; they form a large expanding pool of cells, ready for participation in primary immune responses. The absolute counts of CD45RO+ memory T lymphocytes were similar in infants and adults, albeit with a lower level of expression of CD45RO on infant T lymphocytes. Almost all infant T lymphocytes expressed CD38 throughout the first year of life. The abundant expression of CD38 on an infant's T lymphocytes might be related to a greater metabolic need of the large population of naive untriggered cells that are continually involved in primary immune responses during the first year of life. The high B lymphocyte counts in infants mainly concerned CD38+ B lymphocytes throughout the first year of life. Also, the relative frequencies of CD1c+ and CD5+ B lymphocytes were higher throughout the first year of life than in adults. Therefore, CD1c, CD5, and CD38 could be markers of untriggered B lymphocytes. In conclusion, our longitudinal survey of T and B lymphocytes, NK cells, and their subpopulations during the first year of life helps to complete the picture of lymphocyte development in infants. This information contributes to the correct interpretation of data from infants with possible immune disorders.

Antigens, CD↗