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PubMed2006

Change in pulse wave velocity throughout normal pregnancy and its value in predicting pregnancy-induced hypertension: a longitudinal study.

OBJECTIVE: We longitudinally examined the changes of brachial to ankle distensibility using pulse wave velocity (PWV) throughout pregnancy and its difference between normal pregnancy and pregnancy-induced hypertension (PIH) groups. STUDY DESIGN: One hundred and eighty-three pregnant women were included in this study. The PWV examinations were performed in a longitudinal way during the first, second, and third trimesters of pregnancy, and immediately and 1 month after delivery. RESULTS: In normal pregnancies, the PWV significantly decreased at the second trimester, increased from the third trimester through immediately after delivery, and decreased again at 1 month after delivery. In PIH patients, it increased in proportion to the progression of gestation. CONCLUSION: We monitored the longitudinal changes in PWV and constructed a PWV normogram during pregnancy. The predictive value of PWV and blood pressure for PIH was higher than that of blood pressure alone, suggesting the usefulness of measuring PWV to predict PIH.

Adolescent↗
PubMed1998

Body morphology in adolescent girls with anorexia nervosa: a short-term longitudinal study.

Changes in body morphology of anorectic girls during illness as well as during the treatment period were studied using data on 23 anthropometric traits. The sample consisted of 20 adolescent girls, aged 16.05 +/- 2.21 years. Girls with shorter duration of anorexia nervosa have larger amounts of fat and muscle tissue on the upper arm, as well as thicker subcutaneous fat tissue of the trunk, than the girls with longer duration of illness. These differences remain even after the treatment period. Growth rate of girls with longer duration of illness has been decreased. Slight changes in the latent structure of body morphology in anorectic girls at the end of hospitalisation in comparison with those at the beginning of hospitalisation were observed. The above-mentioned changes could have resulted from greater relative increase of fat than muscular tissue mass during hospitalisation and possible difference in the sequence of fat gain between the trunk and the extremities. Further studies are needed.

Adolescent↗
PubMed1998

Interpreting bodily changes as illness: a longitudinal study of older adults.

Research on elders' health behavior has largely ignored the stage between experiencing a bodily change and defining it as an illness. This paper addresses the question of what explains such definitions of bodily complaints as illness symptoms. The issue is examined in a longitudinal study with a random sample of 350 community dwelling persons aged 65 and over. Multiple regression was used to analyze the effects of external stresses, psychological factors and health attitudes as well as contextual variables, on three types of illness representations. These consisted of giving the bodily changes an illness label, initiating contact with a physician, and/or using some form of self care. These illness representations were treated as outcome variables singularly and in combination. The findings revealed that the overall frequency of a person's bodily changes was the best predictor of an illness designation. Other significant predictors at Time 4 of the study included belief in the seriousness of a complaint, the occurrence of prior illness representations and self-assessed health. This research study on the elderly is unique in that it seeks to explain, within a longitudinal design, the intermediate step between the experience of a bodily change and the definition of the change as an illness.

Aged↗
PubMed2005

Cancellous bone changes in hip osteoarthritis: a short-term longitudinal study using fractal signature analysis.

OBJECTIVE: To quantify changes to the trabecular structure in the femoral heads of patients with hip osteoarthritis (OA). METHODS: Patients with OA (n=14; F=7), mean (standard deviation age) 50.6 (10.1) years, had macroradiographs at approximately x4 magnification at baseline and 18 months later using a standardized protocol. Following digitization, computerized measurement was obtained of minimum hip joint space width and fractal signature analysis (FSA) measured longitudinal changes separately in the principal compressive (vertical) and horizontal trabeculae at the region of interest within the centre of the head. RESULTS: The patient group had mean annual rate of joint space narrowing of 0.14+/-0.36 mm/yr. FSA detected no significant changes in horizontal trabeculae, whereas the larger principal compressive (vertical) trabeculae (0.96 mm to 1.02 mm) increased significantly in thickness and the fine to medium trabeculae (0.18 mm to 0.54 mm) decreased significantly in number. CONCLUSION: The increased thickness of the larger trabeculae within the compressive structural element of the femoral head is a response to the increase in stress associated with an overall loss of trabeculae in this region, suggesting the presence of an osteoporosis within the femoral head in OA patients.

Female↗
PubMed2002

High-resolution MRI and micro-FE for the evaluation of changes in bone mechanical properties during longitudinal clinical trials: application to calcaneal bone in postmenopausal women after one year of idoxifene treatment.

OBJECTIVE: To investigate whether recently developed in vivo high-resolution magnetic resonance-imaging and micro-finite element techniques can monitor changes in bone mechanical properties during long-term clinical trials aiming at evaluating the efficacy of new drugs for the treatment of osteoporosis. DESIGN: Comparison of baseline and follow-up mechanical parameters calculated using micro-finite element analysis of the calcaneus for subjects participating in a study investigating the effect of idoxifene. BACKGROUND: Contemporary measurements for the evaluation of bone mechanical properties, based on dual-energy X-ray absorptiometry measurements, are not very accurate and require large trial populations. METHODS: A total of 56 postmenopausal subjects received either a placebo, 5 mg or 10 mg per day of idoxifene. Magnetic resonance-images of the calcaneus were made at baseline and after one year. Mechanical parameters of a trabecular volume of interest in the calcaneus were calculated using micro-finite element analysis. RESULTS: Although there were no significant differences between the mean changes in the treated groups and the placebo group, there were significant changes from baseline within groups after one year of treatment. Significant changes, however, were found only for mechanical parameters and only in the treated groups. CONCLUSIONS: The present study is the first demonstration that longitudinal changes in bone mechanical properties due to trabecular micro-architectural changes may be quantified in long-term clinical studies. Since significant changes in mechanical parameters were obtained for the treated groups whereas no significant change in bone mass was found we conclude that the application of these techniques may increase the clinical significance of these trials. RELEVANCE: A precise diagnosis of in vivo bone mechanical properties that accounts for (changes in) trabecular bone architecture is of particular importance for longitudinal clinical trials aiming at evaluating the efficacy of new drugs since it can lead to clinically relevant results from shorter follow-up intervals and may enable a reduction of the number of patients involved in the trial.

Bone Density↗
PubMed2003

A longitudinal study of neuropsychological change in individuals with Parkinson's disease.

Neuropsychological changes in individuals with Parkinson's disease (PD) were studied longitudinally. Sixty-nine idiopathic PD patients, with Mini-Mental State Examination (MMSE) scores falling within normal range, and 37 elderly control participants were given neuropsychological tests twice approximately two years apart. The PD group performed poorer than the control group on Semantic Fluency, Letter Fluency, Modified Wisconsin Card Sorting Task, and Block Design at test time 1. Two years later, the PD group showed significant decline in Semantic and Letter Fluency. A subset of 12 PD patients declined in mental status by second testing (> or =4 MMSE points). Cox proportional-hazards models were used to see if any baseline measures were associated with relative risk of decline in mental status. In the final model, Repetition performance and Age were significantly associated with cognitive decline. Consistent with previous studies, executive function tasks were those most susceptible to disease progression.

Aged↗
PubMed2003

A longitudinal study of neuropsychological change in individuals with Parkinson's disease.

OBJECTIVES: Neuropsychological changes in individuals with Parkinson's disease (PD) were studied longitudinally. METHODS: Sixty-nine idiopathic PD patients, with Mini-Mental State Examination (MMSE) scores falling within normal range, and 37 elderly control participants were given neuropsychological tests twice approximately two years apart. RESULTS: The PD group performed poorer than the control group on Semantic Fluency, Letter Fluency, Modified Wisconsin Card Sorting Task, and Block Design at test time 1. Two years later, the PD group showed significant decline in Semantic and Letter Fluency. A subset of 12 PD patients declined in mental status by second testing (>4 MMSE points). Cox proportional-hazards models were used to see if any baseline measures were associated with relative risk of decline in mental status. In the final model, Repetition performance and Age were significantly associated with cognitive decline. CONCLUSIONS: Consistent with previous studies, executive function tasks were those most susceptible to disease progression.

Aged↗
PubMed1995

Aging in adults with Down syndrome: report from a longitudinal study.

Changes in functioning related to aging were examined in 34 adults (14 females, 20 males) with Down syndrome who were 22 to 56 years of age. Changes in functioning over 3 to 4 years were examined, with age, IQ at entry into the study, and gender considered. Neither effects of age at entry nor change over time were significant, suggesting that changes related to aging in adults with Down syndrome were minimal. In contrast, IQ at entry had a significant effect on all performances, suggesting that any examination of aging must consider intellectual level. Results do not support the idea that adults with Down syndrome show rapid age-related declines in functioning apart from the occurrence of a progressive dementia such as Alzheimer's disease.

Adult↗
PubMed1993

Effects of a community-based service on adaptive and maladaptive behaviours: a longitudinal study.

Changes in skill acquisition and problem behaviour, contingent upon the introduction of a new community-based service, were compared for subjects in three different residential settings: supported accommodation; hospital; and private family homes. Results over a 5-year period indicate links between service contact and increases in skill level, together with an increase in problem behaviour for subjects who moved from hospital to supported accommodation. The interpretation of client income in the context of service process is discussed.

Adult↗
PubMed1994

Measurement invariance in longitudinal clinical research assuming change from development and intervention.

Valid and reliable measures of psychological and behavioral constructs are critical to clinical research, particularly longitudinal treatment research, in which multiple groups are compared over time for possible changes within and between constructs as a result of intervention or development. Structural equation modeling (SEM) analysis is a class of statistical procedures that can be used to test multiple hypotheses about these relationships simultaneously while controlling for measurement error. The procedures have been applied primarily to testing between-construct relationships in nonexperimental studies, with relatively little emphasis on establishing whether measures are sufficiently invariant across groups and across time to permit these tests. This article uses an empirical example of a longitudinal experimental prevention study with two groups to illustrate the use of SEM, first, to systematically test measurement invariance across groups at each wave of measurement, and second, after establishing measurement invariance, to test structural invariance longitudinally.

Adolescent↗
PubMed1990

Effects of size on vervet (Cercopithecus aethiops) gait parameters: a longitudinal approach.

Changes in the values of certain locomotor parameters were analyzed over a range of speeds for five immature vervet monkeys sampled at 6 month intervals over approximately a 3 year period. Lateral and diagonal sequence walking gaits and transverse and rotary gallops were commonly used. The monkeys switched from walking to galloping at long cycle durations for their mass, although, as a group, their transition speeds were in agreement with data from other mammals. However, for individual monkeys, transition speed was not consistently dependent on body mass. Cycle and stance durations generally increased with increasing size at each speed for each animal, with the greatest increases occurring at slower speeds. Swing durations increased slightly with size. For any particular individual, speed was highly predictable from cycle (or stance) duration and body mass (or age). However, the multiple regression equations for each animal were significantly different from each other, suggesting that no single equation is satisfactory for all of the individuals within a species.

Aging↗
PubMed1995

Change in job and marital experiences and change in psychological distress: a longitudinal study of dual-earner couples.

Are changes in job quality more closely linked to changes in distress for men than for women? Conversely, are changes in marital quality more closely linked to changes in distress for women than for men? These questions were addressed in a longitudinal analysis of a random sample of 210 full-time employed dual-earner couples. Change over time in job role quality was significantly associated with change over time in distress, and the magnitude of the relationship differed little, if at all, by gender. In contrast, change over time in marital role quality was also associated with change in distress, but the magnitude of the association depended on gender. Among full-time employed married women, change in marital experience was more closely linked to change in distress than among their husbands.

Adult↗
PubMed1988

The effects of Norplant-2 rods on clinical chemistry in Singaporean acceptors after 1 year of use: haemostatic changes.

A longitudinal study of coagulation parameters was carried out on 100 Singapore acceptors using the levonorgestrel subdermal implants Norplant-2 rods for contraceptive purposes. At the end of 1 year of use, results from this on-going study indicates that these acceptors have an enhanced potential for hypercoagulation with a significant shortening of their prothrombin time and activated partial thromboplastin time. They also have an increased predisposition to thrombosis as evidenced by significant increases in platelet count and aggregability. A number of other parameters achieved statistically significant differences by the end of one year but since the results were within the normal accepted range, they were therefore unlikely to be of much clinical importance.

Adult↗
PubMed1988

The effects of Norplant on clinical chemistry in Singaporean acceptors after 1 year of use: I. Haemostatic changes.

A longitudinal study of coagulation parameters was carried out on 100 Singaporean acceptors using the levonorgestrel subdermal implants NORPLANT for contraceptive purposes. At the end of 1 year of use, results from this on-going study indicate that these subjects may have an increased predisposition to thrombosis as evidenced by significant increase in platelet count and aggregability. The results also show that NORPLANT acceptors may have an enhanced potential for hypercoagulation - with a significant shortening of their Prothrombin Time and Activated Partial Thromboplastin Time and increases in Factors V and X. As previously documented, mean values for haemoglobin and haematocrit were significantly elevated by the end of 1 year. A number of other parameters achieved statistically significant differences by the end of 1 year but these were probably due to the large sample size involved and were therefore not likely to be of much clinical importance.

Adult↗
PubMed1989

Two-year follow-up of changes in clinical chemistry in Singaporean Norplant acceptors: haemostatic changes.

A longitudinal study of coagulation parameters was carried out on 100 Singaporean acceptors using Norplant for contraceptive purposes. At the end of 2 years of use, results from this ongoing study indicate that these acceptors continue to have an increased predisposition to thrombosis as evidenced by significant increases in platelet count and aggregability. The shortened but stable prothrombin time and activated partial thromboplastin time and increase in certain coagulation factors indicate that Norplant acceptors still have a possible potential for hypercoagulation at the end of two years of use.

Blood Coagulation↗
PubMed1986

Radiographic quantification of alveolar bone level changes. A 2-year longitudinal study in man.

The "random burst" theory has recently been proposed as an explanation of the pattern of periodontal disease progression. The theory predicts that the progression of bone loss at individual sites is not dependent upon previous bone loss and age. A longitudinal radiographic study was designed to test this hypothesis, and to describe the changes in bone level over 2 years in a group of 180 subjects (18-68 years of age) who were not under systematic periodontal treatment. The results indicated that 94% of the sites did not show significant changes in the alveolar bone level during the observation period. The mean annual bone loss for the total population was 0.11 mm. By regressing longitudinal bone loss upon age, it was shown that the rate of bone loss increased rapidly between 33 and 56 years of age while a different pattern was shown for the age intervals 18-32 and 57-68 years. Also, the rate of bone loss increased with increasing initial bone loss. This was less evident in the oldest age group. It was concluded that the progression of bone loss in the present material is consistent with a "burst" theory. However, the progression did not occur randomly with regard to previous loss of alveolar bone and time.

Adolescent↗
PubMed2006

Longitudinal age-related changes in 24-hour total heart beats and premature beats and their relationship in healthy elderly subjects.

The aim of this study was to conduct a longitudinal follow-up on age-related changes in 24-hour total heart beats (THBs) and total premature beats and their correlations in healthy elderly subjects. In 15 healthy elderly subjects (mean age, 70.0 +/- 4.1, age range at 1st recording, 64 to 80 years, 10 females, 5 males), we conducted Holter monitoring twice at an interval of 15 years and analysed age-related changes in THBs, atrial premature beats (APBs), and ventricular premature beats (VPBs), as well as their correlations. The results indicated that THBs, APBs, and VPBs all significantly increased with age in the healthy elderly subjects at a mean age of 70.0 +/- 4.1 (THB: 91074.1 +/- 11515.3 versus 99457.5 +/- 12131.0; P = 0.0004, APB:119.2 +/- 97.8 versus 884.4 +/- 1193.8; P = 0.0008, VPB: 15.2 +/- 53.6 versus 140.7 +/- 228.9; P = 0.0328). Moreover, we divided the subjects into increase and nonincrease groups based on the age-related changes in APB and VPB for 15 years ([n]; Inc-APB: Noninc-APB = 6 : 9, Inc-VPB: Noninc-VPB = 5 : 10). In the increase groups, premature beats tended to increase in proportion to changes in THBs with age (APB: Y = 207.488 + 0.136 X, r = 0.848, P = 0.0303; VPB: Y = -27.594 + 0.028 X, r = 0.727, P = 0.1921). In conclusion, this 15-year follow-up of Holter recordings in healthy elderly subjects revealed that THBs, APBs, and VPBs increased with age, and that the increases in premature beats, especially APBs, were in proportion to those in THBs.

Adolescent↗