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PubMed1994

Longitudinal analysis of somatic development in paediatric patients with IDDM: genetic influences on height and weight.

Normal growth and development, as well as the prevention of overweight, are major goals in the treatment of paediatric patients with insulin-dependent diabetes mellitus (IDDM). We therefore evaluated longitudinally the anthropometric measurements of height and weight, as well as bone age, in an unselected group of 389 patients with IDDM treated at one institution. In order to identify genetic influences on these parameters, height and weight were determined in 186 unaffected siblings and 177 pairs of parents. At diagnosis, patients were slightly taller than average (median z score: +0.37). During the subsequent course of diabetes, age-adjusted heights decreased progressively for the first 9 years, catching up again after more than 10 years of diabetes. Bone ages were progressively retarded with increasing duration of diabetes. In 76 patients of 18 years or older, median z-score for height was +0.30, not different from their unaffected siblings (median z-score: +0.22). The correlation with midparental height was identical for diabetic and nondiabetic siblings (r = 0.43). In contrast, children with diabetes were significantly heavier (z-score for weight: +0.74 compared to +0.34 in unaffected siblings; p < 0.002). Obesity developed primarily during and after puberty. We conclude that: 1) during the course of diabetes, longitudinal growth is temporarily reduced and maturation is delayed in children with diabetes compared to unaffected siblings. However, this effect of diabetes is transient and small compared to genetic influences on height in an individual child. 2) As a group, children with IDDM become significantly overweight, which is likely to increase the cardiovascular risk during adulthood.

Age Determination by Skeleton↗
PubMed1980

Somatic complaints in males as a function of age and neuroticism: a longitudinal analysis.

Previous research has shown that both age and neuroticism are correlated with total scores on self-report health inventories; the present study concerns the influence of these two factors on reports of physical complaints in various bodily systems. Six- and twelve-year longitudinal analyses of the physical health sections (A-L) of the Cornell medical Index were supplemented with cross-and time-sequential analyses. Subjects, aged 17-97, were taken from a group of 1038 male participants in the Baltimore Longitudinal Study of Aging. Results showed that problems in sensory, cardiovascular, and genitourinary systems increased with age, while health habits improved. More neurotic subjects, as measured by the psychiatric sections (M-R) of the CMId and the Emotional Stability Scale of the GZTS showed higher levels of endorsements on all sections. These results suggest that age does not produce a generalized increase in physical complaints; instead, specific age-related symptoms show increases. Implications of these findings for research involving self-assessments of health are discussed.

Adult↗
PubMed1997

Patterns of concordance between hair assays and urinalysis for cocaine: longitudinal analysis of probationers in Pinellas County, Florida.

This chapter reports on a field trial involving the application of hair assays to a probation population. The objectives were to evaluate the general reactions of probation officers and probationers to the collection of hair samples, to compare the outcomes of the hair samples with the outcomes of urinalyses (which the probationers undergo routinely), to note and react to differences in the prevalence as indicated by the two assay types, and to assess the general monitoring potential for hair assays in a correctional setting. In general, hair assays showed an increased capability of detecting cocaine exposure when compared to urinalysis. The detection of cannabis was, however, problematic for hair. The hair assays, using urine as a comparator, appeared to result in several apparent false negatives for cannabinoids. There were no false negatives for cocaine, and an approximately fourfold increase in the detection rate when compared to urine. The collection of hair samples was not difficult and the cooperation of the probationers was quite good. Probation officers appear to prefer the use of hair specimens to urine specimen collection, and appeared enthusiastic about the potential use of hair analysis in their routine monitoring of clients.

Biological Assay↗
PubMed2005

Longitudinal analysis of the reciprocal effects of self-assessed global health and depressive symptoms.

This study examined whether a reciprocal relationship exists between measures of self-assessed global health and depressive symptoms, net of covariates that included chronic illness, functional disability, education, income, gender, race, and age. Analyses of five waves of data from the Rand version of the Health and Retirement Survey (N=7,475), using an autoregressive, cross-lagged panel design, indicated that self-assessed overall health had a modest but statistically significant and consistent effect on depressive symptoms. In contrast, the level of depressive symptoms had a statistically nonsignificant effect on self-assessed health. There has been growing interest in identifying the factors that inform self-assessments of overall health. The present findings indicate that self-assessed global health is not simply a manifestation of depressed affect.

Aged↗
PubMed2003

Longitudinal analysis of data with multiple binary category choices.

In many experiments, subjects mark all categories that apply when responding to a cafeteria or multiple-response question. One exact and two approximate permutation methods are described to analyze binary answers to multiple-response questions in longitudinal experimental designs, wherein the same or matched subjects respond to the same multiple-response question over two or more trials. The described methods provide probabilities, under the null hypothesis, that the multiple binary responses do not differ over trials.

Choice Behavior↗
PubMed2005

Ghrelin, adiponectin, and leptin do not predict long-term changes in weight and body mass index in older adults: longitudinal analysis of the Rancho Bernardo cohort.

Ghrelin, leptin, and adiponectin are associated with body size in cross-sectional studies; it is unknown whether these hormones predict long-term changes in body size. Multilevel models were used to study associations between fasting serum hormones, measured in 698 men and 619 women (60-91 years) in samples collected at baseline (1984-1987), and changes in weight and body mass index, assessed repeatedly over a follow-up period of up to 18 years (median, 4.7 years). Baseline weight was -1.5 kg lower for a one-standard-deviation increment in ghrelin and -3.3 kg lower for a one-standard-deviation increment in adiponectin, similar in men and women. For leptin, baseline weight was 12.1 kg higher for a one-standard-deviation increment in men, compared with 5.7 kg in women (sex-interaction p < or = 0.0001). Ghrelin and adiponectin did not affect weight change; their associations with weight were constant over time, indicated by nonsignificant hormone-by-time interactions. The positive association between leptin and weight became slightly weaker over time. Results were similar when investigating repeated measures of body mass index. From this analysis of Rancho Bernardo Study data, the authors conclude that ghrelin, adiponectin, and leptin do not predict weight gain beyond reflecting the influence of attained body size on future changes in weight or body mass index.

Adiponectin↗
PubMedDate not supplied

Emergence and constructvalidation of the big five factors in early childhood: a longitudinal analysis of their ontogeny in Sweden.

Researchers have shown that the five major dimensions of personality (extraversion, agreeableness, conscientiousness, neuroticism, and openness to experience) and two additional factors (irritability and positive activity) are evident from adolescence. This study attempted to replicate and extend these results in a longitudinal study of 102 Swedish children, followed from 2.3 to 15.2 years of age. Item analyses revealed consistently reliable irritability, conscientiousness, and positive activity factors, whereas the internal reliability of the extraversion, agreeableness, neuroticism, and openness to experience factors increased over time. Irritability and positive activity were not independent of the other factors. Scores on most of the personality factors were fairly stable over time. Over time, children became less extraverted, more agreeable, and more conscientious. Neuroticism and openness to experience increased in Phase III, although openness then decreased in Phase V. Validity of the original factors was demonstrated by correlations with independent assessments of the children's cognitive performance and adjustment to school.

Achievement↗
PubMedDate not supplied

Mixed-longitudinal analysis of growth data from Malian adolescent girls: evidence for compensatory gain?

Cross-sectional data have previously indicated poor growth and development among adolescent girls in Mali. These data have shown that Malian girls are shorter and lighter than their United States female counterparts. Many studies suggest that this evidence of poor growth and development is due to a combination of poor nutrient intake, high-energy expenditure, and poor access to health care. At adolescence, individuals rarely follow a standard pattern of growth due to different biological timetables and expressions of pubertal growth. By examining velocity of growth, researchers can recognize developmental patterns such as compensatory gain. This study examines the growth rates of Malian girls over a 6-month period. Anthropometric data were collected from a total of 1,045 adolescent girls ages 10-17 years. Height and weights were collected twice from the Segou Coura community in the town of Segou and from the Dioro Arrondissement in 1997. From these data, mixed longitudinal analyses were conducted. Both the height and weight velocity data showed patterns of delayed growth rates when compared with American girls. Although Malian girls are similar to American girls in that they tend to reach their peak height velocity at age 12, the Malian girls demonstrate a longer growth spurt than the American girls. This evidence of greater height velocity may be an indication of compensatory growth, or compensatory gain, and is partially supported from cross-sectional data. While these Malian data do not show much evidence that certain stressors are relieved during adolescence, only more extensive longitudinal data can more fairly examine the issue.

Adolescent↗
PubMed1997

Evidence that the apolipoprotein E-genotype effects on lipid levels can change with age in males: a longitudinal analysis.

We previously reported that change, with age, in plasma levels of total cholesterol (TC) and LDL cholesterol (LDL-C) differed between apolipoprotein E (APOE) genotypes epsilon 3 epsilon 3 and epsilon 3 epsilon 4, in a sample of 77 older, unrelated males. By use of a larger sample from that cohort, followed longitudinally during 1969-87, the change in TC and in LDL-C, between the epsilon 3 epsilon 3 and epsilon 3 epsilon 4 APOE genotypes, over three exams, was reanalyzed. Additionally, the change in triglycerides (TG) and in HDL-cholesterol (HDL-C), between the epsilon 3 epsilon 3 and epsilon 3 epsilon 4 APOE genotypes-as well as the differences between the epsilon 3 epsilon 3 and epsilon 3 epsilon 2 genotypes, for TC, LDL-C, TG, and HDL-C-were contrasted over the three exams. At exam 1 TG was higher in the epsilon 3 epsilon 4 group than in the epsilon 3 epsilon 3 group (mean age 48 years), and at exams 2 and exam 3 (mean ages 58 and 63 years, respectively) it was similar (P = .009 for the exam-by-genotype-interaction effect in the repeated-measures analysis). A similar trend was seen for TC (P = .03), yet previously detected LDL-C effects were not apparent (P = .46). Those with the epsilon 3 epsilon 2 genotype had higher TG and lower LDL-C and TC at each exam than were seen in those with the epsilon 3 epsilon 3 genotype, although the differences in the values were not always statistically significant. Differences in TC, LDL-C, and TG, between the epsilon 3 epsilon 2-genotype and epsilon 3 epsilon 3-genotype groups, did not significantly change over the three exams. HDL-C levels were relatively stable over the exams; however, the exam-by-genotype interaction was significant for the epsilon 3 epsilon 2 genotype versus the epsilon 3 epsilon 3 genotype (P = .02). The epsilon 4 allele effects on TG and TC changed between longitudinal exams and may be age dependent. Changes, with age, in the effect of the epsilon 3 epsilon 4 genotype on lipids may impact the risk of developing atherosclerotic disease.

Aged↗
PubMed2006

Longitudinal analysis of immune cell phenotypes in early stage multiple sclerosis: distinctive patterns characterize MRI-active patients.

To investigate whether peripheral immune abnormalities are associated with brain inflammation in multiple sclerosis, and whether differences in MRI activity are paralleled by changes in leukocyte composition, we conducted a prospective longitudinal study in patients at their clinical onset. Twenty patients presenting a first inflammatory event in the central nervous system suggestive of multiple sclerosis underwent, every 45 days for one year, immunophenotyping of 98 blood cell subsets together with brain MRI and clinical evaluation. Six patients showed intense MRI activity, six patients did not display MRI activity, while the remaining 8 patients had low (i.e. intermediate) MRI activity during the follow-up. Our results show that MRI-active and MRI-inactive patients display significant differences in ten lymphocyte subsets. Among these, there are both effector (CCR7-CD45RA-CD4+ alphabeta T cells, CCR5+ gammadelta T cells) and regulatory (DN CD28+ alphabeta T cells and CD25+CD8+ alphabeta T cells) lymphocytes pertaining to the innate and the acquired arms of the immune system. Moreover, these differences were, upon employment of a class prediction procedure based on "support vector machines" algorithm utilizing leave-one-out cross validation procedures, able to correctly assign patients to their respective MRI activity group. All 6 MRI-active and 6 MRI-inactive patients were correctly classified, and, upon application of a class prediction model in an unsupervised manner to the 8 patients with intermediate MRI activity, 6 were predicted as MRI-active and 2 as MRI-inactive patients. Also, when the mean values of the first three time points (T0, T1 and T2) were used for the prediction of all patients, the selected lymphocyte subsets correctly classified 90% of patients. Sensitivity was 91.7% and specificity was 87.5%. These results provide evidence showing that brain inflammation in multiple sclerosis is associated with distinct changes in peripheral lymphocyte subsets, and raise the possibility that the identified subsets may, after adequate validation, assist in the prediction of MRI activity in the early stages of multiple sclerosis.

Adult↗
PubMed2005

Living alone with Alzheimer's disease: cross-sectional and longitudinal analysis in the REAL.FR Study.

OBJECTIVES: The purpose of this study was to examine the characteristics of Alzheimer's disease (AD) patients living alone and to describe the rate of cognitive and functional impairment after a one-year follow-up. DESIGN AND SETTING: In a prospective longitudinal study conducted by the French network on Alzheimer's disease (the REAL.FR study), 677 older community-dwelling AD patients were interviewed and completed questionnaires and evaluation scales every 6 months during a one-year follow-up. MEASUREMENTS: All patients were assessed by trained staff who collected data on neuropsychological status using the Mini Mental State Examination (MMSE), behavioural disturbances with the Neuropsychiatric Inventory (NPI) and nutritional status with the Mini Nutritional Assessment (MNA). Patients were assessed for current mobility and function in activities of daily living (ADL) and instrumental activities of daily living (IADL). RESULTS: At inclusion, 28% of the 677 non-institutionalised individuals with AD lived alone. Those who lived alone were significantly older than those who did not, and among them the percentage of women was significantly higher. Patients living alone were at increased risk of malnutrition and were more likely to have a low income than those living with others. Persons with AD living alone made greater use of health services. Dementia stage evaluated by cognitive impairment (MMSE) and ADL disabilities was similar in both groups. At one-year follow-up, the mortality rate was significantly higher in AD patients living with others. Institutionalisation and hospitalisation rates were similar. CONCLUSION: These results draw attention to the fact that elderly persons with AD living alone are a subpopulation with specific needs which require the development of targeted interventions. Further investigation of the factors associated with the lower mortality rate in AD patients living alone is necessary, and the results of long-term follow-up in this prospective study should shed light on this question.

Activities of Daily Living↗
PubMed1998

Longitudinal analysis of the association of human salivary antimicrobial agents with caries increment and cariogenic micro-organisms: a two-year cohort study.

Previous studies of the possible associations of salivary antimicrobial agents with dental caries have given controversial results, obviously mainly because almost all studies have been cross-sectional. Our aim was to find out, in a two-year longitudinal follow-up study, the associations among selected salivary non-immune and immune antimicrobial variables, cariogenic bacteria, and caries increment. The study population was comprised of 63 subjects, all of whom had their 13th birthday during the first study year. In addition to a comprehensive dental examination at baseline and after 2 yrs, paraffin-stimulated whole saliva samples were collected in a standardized way at six-month intervals. Saliva samples were analyzed for flow rate, buffer effect, lysozyme, lactoferrin, total peroxidase activity, hypothiocyanite, thiocyanate, agglutination rate, and total and specific anti-S. mutans IgA and IgG, as well as for numbers of total and mutans streptococci, lactobacilli, and total anaerobic bacteria. Cluster analysis and Spearman-Rank correlation coefficients were used to explore possible associations between and among the studied variables. During the two-year period, a statistically significant increase was observed in flow rate, thiocyanate, agglutination rate, anti-S. mutans IgA antibodies, lactobacilli, and total anaerobes, whereas lysozyme, lactoferrin, and total and anti-S. mutans IgG antibodies declined significantly. Based on various analyses, it can be concluded that, at baseline, total IgG and hypothiocyanite had an inverse relationship with subsequent two-year caries increment, anti-S. mutans IgG antibodies increased with caries development, and mutans streptococci and lactobacilli correlated positively with both baseline caries and caries increment. Total anaerobic microflora was consistently more abundant among caries-free individuals. In spite of the above associations, we conclude that none of the single antimicrobial agents as such has sufficiently strong power to have diagnostic significance in vivo with respect to future caries.

Adolescent↗
PubMed1992

Longitudinal analysis of patient satisfaction among Medicare beneficiaries in different models of health maintenance organizations and fee-for-service care.

Based on a randomly selected nationwide sample of Medicare beneficiaries, this study analyzes changes in patient satisfaction over a one year period for beneficiaries receiving care in a variety of delivery settings: fee for service, group model HMO, staff model HMO, and Independent Practice Association model HMO. The findings reveal the patient satisfaction changes significantly over a one year period, from lower levels of satisfaction to higher levels of satisfaction. The primary explanation for this change in satisfaction is a decline in health status over the same one year period. Additional differences in satisfaction with care were observed for Medicare beneficiaries served by different types of delivery settings with varying degrees of utilization controls.

Aged↗
PubMed2002

Longitudinal analysis of length growth in the chimpanzee (Pan troglodytes).

The adolescent growth spurt in linear dimension in humans is considered to be unique among mammals, but few comparative studies have been done, even on chimpanzees. Growth of the summed length of crown to rump, thigh, and leg was studied longitudinally in 12 chimpanzees. We took body weight growth and reproductive maturation into consideration. Reproductive maturation was monitored by the swelling of sexual skin and menarche in females, and by testicular development in males. We applied two relationships found in humans between body length growth and the environment to the chimpanzees. The first relationship was the robustness of the growth spurt, meaning that the spurt is absent only in individuals under the most severe environmental pressure. Subjects maturing in a favorable or even mediocre environment are anticipated to show the growth spurt. The second relationship was catch-up growth, where, when the environment is ameliorated, growth may be accelerated to attain the target size. Catch-up growth at the end of the juvenile period may mimic the adolescent growth spurt. Results showed that subjects living under favorable conditions did not exhibit a growth spurt, and that it was only the subjects who had delayed growth in the juvenile period that showed a spurt in adolescence, the period when reproductive maturation occurred. Although we have concluded that chimpanzees do not have an adolescent growth spurt, except in cases of catch-up growth, this does not mean that they have a different growth pattern from that of humans. The absence of a growth spurt may be associated with adaptations to chimpanzee patrilineal society, where adolescent males are incorporated into the adult hierarchy at a low rank.

Animals↗
PubMed2002

A longitudinal analysis of wheezing in young children: the independent effects of early life exposure to house dust endotoxin, allergens, and pets.

BACKGROUND: It has been postulated that exposure to bacterial endotoxins and animals early in life might confer protection against the development of asthma and allergies. OBJECTIVE: We investigated the longitudinal effects of exposure to house dust endotoxin (HDE), allergen levels, and the presence of a dog in the home on wheezing in young children over a 4-year period. METHODS: Two hundred twenty-six children younger than 5 years were followed for 4 years. Endotoxin and allergen levels were measured from house dust collected at baseline. Longitudinal associations were investigated by using a proportional hazards technique that allowed for multiple outcomes per subject. RESULTS: Exposure to high concentrations of HDE of greater than the median level was associated with an increased risk for wheezing over the period of observation (multivariate relative risk, 1.52; 95 % CI, 1.07-2.14), but this risk rapidly decreased over time (P for trend =.005). Exposure to cockroach allergen was associated with increased risk for wheezing, whereas exposure to cat allergen and the presence of a dog in the home were both associated with decreased risk for wheezing. The risks associated with cockroach allergen, cat allergen, and dog did not change over the period of observation. CONCLUSION: The negative associations between exposures to dogs and cat allergen and wheeze appear to be independent of the effects of endotoxin and suggest that separate mechanisms might mediate the effects of HDE exposure and pet exposure on the developing immune system.

Air Pollution, Indoor↗
PubMedDate not supplied

Teenage smoking: a longitudinal analysis.

This paper examines the binary recurrent outcome "teenage smoking" within a statistical modelling paradigm. The proposed statistical modelling relates smoking to a set of explanatory variables, which include subjective as well as objective measures. In order to assess the degree to which explanatory variables influence smoking, an adequate statistical model must handle the possibility that substantial variation between respondents will be due to omitted variables, multicollinearity and past behaviour. An earlier paper, using a secondary cross-sectional data source, concluded that an investigation of smoking needs to be based on longitudinal data using appropriate statistical modelling. The same data source provided observations on young adults over a period of 2 years. For comparison purposes, the same cross-sectional model was fitted to the longitudinal data. The results suggest there may be substantial heterogeneity due to omitted variables in the data and complex inter-relationships between observed explanatory variables leading to underestimation. Longitudinal data provide additional flexibility to control for omitted variables and are necessary to investigate dynamic social processes such as smoking. The results from our analysis suggest that the effects of variables reported in the literature on teenage smoking may be overestimated. For example, the role of peer pressure may not be as clear as it has been made out to be.

Adolescent↗