Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “longitudinal changes”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 631 records · Page 35Linked to original sources
PubMed2000

Changes in bladder contractility and compliance due to urethral obstruction: a longitudinal followup of guinea pigs.

PURPOSE: We established the longitudinal changes in bladder contractility and compliance as a result of urethral obstruction using a guinea pig model. MATERIALS AND METHODS: Obstruction was induced in guinea pigs by a silver ring around the urethra. Urodynamic studies were performed longitudinally in individual animals. Bladder contractility and compliance were calculated from the measured bladder pressure and urine flow rate. RESULTS: Bladder contractility developed in distinct phases. It reached a maximum 200% increase after an average of 3.25 weeks concomitant with an almost 2-fold increase in urethral resistance, remained 150% to 200% increased during weeks 4 to 7 and then decreased to starting levels again, while urethral resistance remained almost 2-fold increased. Bladder compliance decreased by 80% during the first 3 weeks and continued to decrease to 5% of its original value after 10 to 11 weeks. CONCLUSIONS: Our data indicate that as a result of obstruction bladder function passes through a specific sequence of stages, including first a compensatory increase in contractility, then a stabilization phase and finally a decompensation state. In contrast bladder compliance shows a continuous decrease. The data suggest that for assessing how far a bladder has deteriorated due to obstruction a combination of functional and structural data may be warranted.

Animals↗
PubMed1985

Determinants of blood pressure changes due to urbanization: a longitudinal study.

Changes in blood pressure (BP) and associated factors which occur on migration from a rural to an urban environment are under observation in a longitudinal study. Blood pressures, heart rate (HR), urinary electrolytes, sociological and anthropometric data are recorded at 0, 3, 6, 12, 18 and 24 months following migration and compared with a cohort of age and sex-matched rural based controls. Data from the first 6 months' follow-up reveal that the migrants' BPs are higher and tend to rise compared with controls, in whom BP falls progressively with time. Changes in body weight and dietary electrolytes appear to explain some of the BP differences, while differences in pulse rates between groups suggest that a further mechanism operative through the autonomic nervous system is responsible for some of the elevation of systolic BP shown amongst migrants, particularly on arrival in the urban area.

Adult↗
PubMed2006

[Stress releasing effect of tissue conditioning materials for interim dentures after implant installation].

PURPOSE: The main objective of this study was to examine the influence of the thickness and its longitudinal change within the limited denture space on the stress releasing effect for installed implants during the healing period of a two-stage procedure. METHODS: As for the tissue conditioning material, Tissue Conditioner (Shofu, Kyoto, Japan) with the designated powder liquid ratio was used. The force transmitted to the implant with the material 5 min after the mixing was measured by a miniature pressure sensor in the position of the implant head (Kyowa, Tokyo, Japan). Measurements were repeated with the material preserved in the water for one and two weeks. Load of 2 kg was applied with a 3-mm diameter round tip using a static loading machine for 2 min to the center of the flat type denture model. The model consisted of denture, mucosa, tissue conditioning material and implant where the first three variables were changed as in the oral cavity. Influence of thickness of each variable was examined longitudinally. RESULTS: Force measured with any thickness of tissue conditioning material was smaller than that without the material. The stress releasing effect did not change with change of the longitudinal material property up to two weeks. CONCLUSIONS: Within the limitations of our study, it was suggested that the stress releasing effect of the tissue conditioning material for the installed implant was not influenced by the thickness or change of longitudinal property.

Dental Implants↗
PubMed2005

A prospective cohort study among new Chinese coal miners: the early pattern of lung function change.

AIMS: To investigate the early pattern of longitudinal change in forced expiratory volume in 1 second (FEV1) among new Chinese coal miners, and the relation between coal mine dust exposure and the decline of lung function. METHODS: The early pattern of lung function changes in 317 newly hired Chinese underground coal miners was compared to 132 referents. This three year prospective cohort study involved a pre-employment and 15 follow up health surveys, including a questionnaire and spirometry tests. Twice a month, total and respirable dust area sampling was done. The authors used a two stage analysis and a linear mixed effects model approach to analyse the longitudinal spirometry data, and to investigate the changes in FEV1 over time, controlling for age, height, pack years of smoking, mean respirable dust concentration, the room temperature during testing, and the groupxtime interaction terms. RESULTS: FEV1 change over time in new miners is non-linear. New miners experience initial rapid FEV1 declines, primarily during the first year of mining, little change during the second year, and partial recovery during the third year. Both linear and quadratic time trends in FEV1 change are highly significant. Smoking miners lost more FEV1 than non-smokers. Referents, all age less than 20 years, showed continued lung growth, whereas the miners who were under age 20 exhibited a decline in FEV1. CONCLUSION: Dust and smoking affect lung function in young, newly hired Chinese coal miners. FEV1 change over the first three years of employment is non-linear. The findings have implications for both methods and interpretation of medical screening in coal mining and other dusty work: during the first several years of employment more frequent testing may be desirable, and caution is required in interpreting early FEV1 declines.

Adolescent↗
PubMedDate not supplied

Changes in ADL dependence and aspects of usability following housing adaptation--a longitudinal perspective.

OBJECTIVE: To investigate longitudinal changes in activities of daily living (ADL) dependence and aspects of usability in housing among clients receiving housing adaptation grants in Sweden. METHODS: The ADL Staircase and the Usability in My Home instruments were used to collect data on three occasions: at baseline 1 month before housing adaptation, at follow-ups 2 to 3 months after housing adaptation completion, and after another 6 to 7 months. In all, 131 clients, living in ordinary housing 24 to 93 years of age were consecutively enrolled. RESULTS: Overall ADL dependence did not change significantly whereas dependence in "Bathing" decreased over time. "Activity aspects" and "Personal and social aspects" of usability improved at different phases in the process. CONCLUSION: This study delivers new insights about the complexity of longitudinal person-environment-activity transactions, specifically targeting activity and usability. The results are useful for developing efficient strategies for evaluating housing adaptations within occupational therapy practice and research.

Activities of Daily Living↗
PubMed2004

Changes in dental arch measurements of young adults with normal occlusion--a longitudinal study.

This study evaluates the longitudinal changes in occlusal dimensions in young adults. The sample was composed of 27 individuals (13 male and 14 female individuals) who presented dental Class I and normal occlusion, according to the inclusion protocol. All teeth were present except for the third molars. The mean age of the subjects was 21 years and two months initially and 28 years and four months at the end of the observation period. The measurements collected in both arches were overbite, overjet, intercanine and intermolar distances, irregularity index, and perimeter. All measurements were taken from study dental casts by a calibrated operator, using a digital caliper. The paired t-test was used to evaluate the changes, using the difference between the initial and final mean measurements. Data indicated that the overbite increased 0.39 mm, the incisor irregularity increased 0.38 mm in the upper arch and 0.54 mm in the lower arch, and the arch perimeter decreased 0.67 mm in the upper arch and 0.71 mm in the lower arch (P > .05). The other measurements did not show significant changes. No sexual dimorphism was observed. It could be concluded that occlusal dimensions change throughout adult life. In the sample studied, changes were statistically significant for overbite, incisors irregularity, and arch perimeter after a mean period of seven years and two months. These changes can be observed in both sexes.

Adolescent↗
PubMed1993

Changes in periodontal status of children and young adolescents: a one year longitudinal study.

The purpose of the present study was to describe longitudinal changes in accumulation of dental plaque and gingival inflammation, and their effect on changes in sulcus depth of children and young adolescents. Forty one boys and 37 girls aged 1-12 years living in a rural community in Israel were included in the study. At baseline and 12 months later, Loe's Plaque Index (PlI) and Gingival Index (GI), and sulcus depth were examined. Boys' mean age was significantly lower than girls' mean age (6.04 + 2.76 years, and 7.68 + 2.84 years respectively). PlI, GI and sulcus depth were higher in the 12-month examination compared to baseline. PlI was slightly higher in boys, while GI was slightly higher in girls. These differences however, were not statistically significant. At baseline, sulcus depth was significantly greater in girls than in boys, while at 12 months the difference was not significant. The children were grouped by age as follows: 1-5 years, 6-9 years and 10-12 years. PlI and GI mean scores were significantly higher among the 6-9-year-old individuals. Mean sulcus depth for the 10-12-year-old children was greater than that of the 6-9-year-olds at baseline and after 12 months. The effect of age, PlI and GI on the outcome variable (sulcus depth) was examined using a correlation matrix. At baseline, age showed the highest correlation (r = 0.659) followed by GI (r = 0.364) and PlI (r = 0.123). The same pattern was also observed at the 12 months examination.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Distribution↗
PubMed1996

How does young people's alcohol consumption change during the transition to early adulthood? A longitudinal study of changes at aggregate and individual level.

We have analysed data from a longitudinal representative study to explore aggregate and individual level changes in alcohol use from late adolescence to early adulthood. The sample, which consisted of 2000 Norwegians, was assessed at ages 19-22, 21-24 and 25-28 years. Only a bare majority of the respondents reduced their alcohol intake during the course of the study, whereas a substantial proportion showed an increase. The initial drinking level in individuals whose consumption declined was quite high, and the opposite was true for those who increased their consumption. The findings seemed to reflect true changes, implying that they only could be attributed to measurement errors to a limited extent. The stability in absolute alcohol intake was rather low, especially at the very high consumption levels. However, the respondents clearly tended to maintain their relative drinking position over time. Furthermore, the very high consumers were actually somewhat more apt than others to hold their position relative to the group. In contrast to previous research, these results thus suggest that there is a substantial stability in alcohol use over time. This in turn underscores the importance of implementing preventive programmes targeted towards factors that promote heavy drinking in adolescents.

Adolescent↗
PubMed2004

Effects of vitamin D and estrogen receptor gene polymorphisms on the changes in lumbar bone mineral density with multiple pregnancies in Japanese women.

BACKGROUND: Our aims were to follow the longitudinal changes in lumbar spine bone mineral density (BMD) with multiple pregnancies, and to study whether polymorphisms in the vitamin D receptor (VDR) and estrogen receptor (ER) genes may influence the results. METHODS: We repeatedly measured the BMD of the lumbar spine (L2-L4) of 133 women who had undergone two successive pregnancies and 73 non-pregnant controls, and analysed the restriction fragment length polymorphisms using restriction endonucleases TaqI, ApaI and FokI for the VDR gene, and PvuII and XbaI for the ER gene. RESULTS: Cases and controls had no significant differences in the longitudinal BMD changes. The mean percentage change in lumbar BMD (DeltaBMD%) of the women with the XX/Xx genotype was significantly lower than that of the women with the xx genotype after adjusting for age at each delivery, BMD of the first scan, and interval between the scans (0.2 +/- 3.3 versus 2.0 +/- 4.2%; P=0.030, analysis of covariance). Multiple regression analyses to evaluate the contribution of the XbaI polymorphism of the ER gene on DeltaBMD% showed that the percentage decrease in BMD was greater for women lacking the XbaI restriction site (adjusted R2=0.188, P<0.0001). CONCLUSIONS: The present study suggests that the DeltaBMD% was significantly influenced by the XbaI polymorphism of the ER gene.

Adult↗
PubMed2001

Longitudinal muscle strength changes in older adults: influence of muscle mass, physical activity, and health.

The longitudinal changes in isokinetic strength of knee and elbow extensors and flexors, muscle mass, physical activity, and health were examined in 120 subjects initially 46 to 78 years old. Sixty-eight women and 52 men were reexamined after 9.7 +/- 1.1 years. The rates of decline in isokinetic strength averaged 14% per decade for knee extensors and 16% per decade for knee flexors in men and women. Women demonstrated slower rates of decline in elbow extensors and flexors (2% per decade) than men (12% per decade). Older subjects demonstrated a greater rate of decline in strength. In men, longitudinal rates of decline of leg muscle strength were approximately 60% greater than estimates from a cross-sectional analysis in the same population. The change in leg strength was directly related to the change in muscle mass in both men and women, and it was inversely related to the change in medication use in men. Physical activity declined yet was not directly associated with strength changes. Although muscle mass changes influenced the magnitude of the strength changes over time, strength declines in spite of muscle mass maintenance or even gain emphasize the need to explore the contribution of other cellular, neural, or metabolic mediators of strength changes.

Aged↗
PubMed2001

Prospective study of hepatic, renal, and haematological surveillance in hazardous materials firefighters.

OBJECTIVES: To evaluate possible health effects related to work with hazardous materials as measured by end organ effect markers in a large cohort over about 2 years, and in a subcohort over 5 years. METHODS: Hepatic, renal, and haematological variables were analysed from 1996-98 in hazardous materials firefighters including 288 hazardous materials technicians (81%) and 68 support workers (19%). The same end organ effect markers in a subcohort of the technicians were also analysed (n=35) from 1993-98. Support workers were considered as controls because they are also firefighters, but had a low potential exposure to hazardous materials. RESULTS: During the study period, no serious injuries or exposures were reported. For the end organ effect markers studied, no significant differences were found between technicians and support workers at either year 1 or year 3. After adjustment for a change in laboratory, no significant longitudinal changes were found within groups for any of the markers except for creatinine which decreased for both technicians (p<0.001) and controls (p<0.01). CONCLUSIONS: Health effects related to work are infrequent among hazardous materials technicians. Haematological, hepatic, and renal testing is not required on an annual basis and has limited use in detecting health effects in hazardous materials technicians.

Adult↗
PubMed1990

[Changes of the arch form and occlusion of the deciduous open bite cases: a longitudinal study].

The purpose of this study was to determine the characteristics and longitudinal changes of the arch morphology and occulusion of the deciduous open bite cases. The materials used in this study were the serial plaster casts of 40 Japanese children with deciduous open bite, and they were measured with the three dimentional system. The following results were obtained: 1. The form of dental arch with open bite in the early primary dentition changed remarkably in the maxilla but little in the mandible. In children with open bite, the maxillary intercanine distance was narrower, the maxillary arch length was longer, the palatal height of the front area was higher, but the back one was lower, and the upper central primary incisors were located more forward and upward higher than in children without open bite. 2. In the late primary dentition, the dental arch shape in the spontaneous closure group showed little difference from the control group. However the deciduous upper central incisors of the spontaneous closure group were very remarkably inclined to the palatal side, and the vertical over-jet was larger than that in the control group. The larger the horizontal over-jets were in the early deciduous dentition, the larger the vertical over-jet changed in the late deciduous dentition. 3. In the spontaneous closure group, the point of the dental arch showed a regular changing aspect, in which place marked variation was recognized in the early deciduous dentition as compared with the control group. Because of spontaneous closure, the dental arch shape approached the one of control group rapidly. 4. The result of multivariate analysis indicate that not only discontinuance of thumb-sucking but also many variables of the dental arch shape and occlusal condition may induce spontaneous closure of the open bite within the deciduous dentition term.

Child↗
PubMed2005

Five-year changes in middle ear function for older adults.

Longitudinal changes in tympanometric measures of middle ear function over five years were reported for a large population of older adults. Findings were similar for men and women, for right and left ears, and across age groups from 48 to 92 years. Although some of the mean changes reached statistical significance, the vast majority of observed changes were small in magnitude relative to the observed variability and the tolerances of the measuring instrument. Observed mean changes in Peak Ytm for older adults were quite small and were in the positive direction. This is counter to changes that would be predicted on the basis of increases in the stiffness of the middle ear transmission system with advancing age suggested in earlier reports. Overall, the findings suggest little in the way of functional change in middle ear mechanics over a span of five years in older adults.

Acoustic Impedance Tests↗
PubMed1999

Option-4 algorithm for third generation disc probe: agreement of selected site-specific relative attachment level measurements and detection of longitudinal site-specific attachment level change.

BACKGROUND: Longitudinal site-specific attachment level change (SSAC), identified from serial relative attachment level measurements (RAL), is the principal indicator of progression/regression of periodontal diseases. Many variables confound RAL reproducibility and affect measurement error. The Option-4 algorithm was designed to reduce measurement error and improve accuracy and sensitivity of SSAC detection. The study aimed to evaluate the performance of the Option-4 algorithm. METHODS: A precalibrated clinician recorded full mouth RAL with a third generation disc probe on 4 occasions over 6 months in 16 subjects (mean age 48.1 years) with moderately advanced chronic adult periodontitis (2,312 sites). Option-4 allowed up to 4 RAL recordings per site per visit until 2 values had differences < or =1.0 mm and their mean was < or =1.0 mm from the previous visit mean: the clinician made the selection if these criteria were unfulfilled. RESULTS: Within-visit agreement < or =1.0 mm was > or =99.6%: all within-visit correlation coefficients = 0.98 (P<0.001). At each visit, mean difference in Option-4 values was < 0.05 mm, mean absolute difference (ignoring direction) was < or =.34 mm. Mean site-specific variances ranged from 0.092 mm2 to 0.097 mm2 across all visits. Subject thresholds for site-specific attachment level change (from estimated 95% confidence limits of visit 1 data) ranged from 0.52 mm to 0.67 mm. Linear SSAC (by linear regression) and between-visit patterns of SSAC were investigated. SSAC was detected in 100% subjects and at 51.0% measured sites. Linear SSAC (R2 > or =0.90: P < or =0.05) occurred at 105 sites (4.5%): 32 sites (1.4%) deteriorated, 73 sites (3.1%) improved. Between-visit SSAC occurred at 1,074 sites (46.5%): 391 sites (16.9%) deteriorated, 295 sites (12.8%) improved, and 388 sites (16.8%) showed exacerbation/remission patterns. CONCLUSIONS: The Option-4 algorithm produced high RAL agreement. Site-specific attachment level change was detected in both directions in 100% subjects and at 51.0% measured sites.

Adult↗
PubMed2004

Bone mineral density changes over two years in first-time users of depot medroxyprogesterone acetate.

OBJECTIVE: To compare longitudinal changes in bone mineral density (BMD) among first-time depot medroxyprogesterone acetate (DMPA) users to women using no hormonal contraception, and evaluate user characteristics associated with that BMD change. DESIGN: Prospective longitudinal study. SETTING: Healthy volunteers in an academic research environment. PATIENT(S): Women, aged 18 to 35, choosing DMPA for contraception (n = 178) and women using no hormonal contraception (n = 145). MAIN OUTCOME MEASURE(S): Hip and spine BMD measured, at three-month intervals for 24 months, by dual energy x-ray absorptiometry. RESULT(S): Mean hip BMD declined 2.8% (SE = 0.034) 12 months following DMPA initiation and 5.8% (SE = 0.096) after 24 months. Mean spine (L1-L3) BMD declined 3.5% (SE = 0.022) and 5.7% (SE = 0.034), respectively, after one and two years of DMPA use. Mean hip and spine BMD of control participants changed less than 0.9% over the same period. Among DMPA users, body mass index (BMI) change was inversely associated with BMD change at the hip, but not at the spine. Calcium intake, physical activity, and smoking did not influence BMD change in either group. CONCLUSION(S): Hip and spine BMD declined after one DMPA injection and this decline continued with each subsequent injection for 24 months. With the exception of increasing BMI among DMPA users, no user characteristics offered protection against DMPA-related BMD loss.

Absorptiometry, Photon↗
PubMed1998

Longitudinal correlates of change in blood pressure in adolescent girls.

The objective of this study was to assess the longitudinal changes in blood pressure in black and white adolescent girls and evaluate potential determinants of changes in blood pressure, including sexual maturation and body size. A total of 1213 black and 1166 white girls, ages 9 or 10 years at study entry, were followed up through age 14 with annual measurements of height, weight, skinfold thickness, stage of sexual maturation, systolic and diastolic blood pressures, and other cardiovascular risk factors. Average blood pressures in black girls were generally 1 to 2 mm Hg higher than in white girls of similar age over the course of the study. Age, race, stage of sexual maturation, height, and body mass index (kg/m2) were all significant univariate predictors of systolic and diastolic blood pressures in longitudinal regression analyses. Black girls had a significantly smaller increase in blood pressure for a given increase in body mass index compared with white girls. The predicted increases in blood pressure per unit increase in body mass index (mm Hg per kg/m2) were as follows: systolic, 0.65+/-0.04 in whites and 0.52+/-0.04 in blacks (P<.001); diastolic fourth Korotkoff phase, 0.31+/-0.04 in whites and 0.15+/-0.03 in blacks (P<.001); and diastolic fifth Korotkoff phase, 0.31+/-0.05 in whites and 0.16+/-0.04 in blacks (P<.001). Understanding of the determinants of the racial differences in blood pressure could provide the rationale for future interventions to reduce the excess cardiovascular mortality in black compared with white women.

Adolescent↗
PubMed2004

A longitudinal study of changes in evoked otoacoustic emissions and pure-tone thresholds as measured in a hearing conservation program.

Non-linear transient-evoked otoacoustic emissions (TEOAEs) at 74dB pSPL, distortion-product otoacoustic emissions (DPOAEs) at 65/45dB SPL and pure-tone audiometry were used to detect noise-induced, inner car changes in a longitudinal study. Repeated-measures ANOVAs were made on the Noise (n=69) and Quiet (n=42) groups. The Noise group's hearing thresholds increased by 1.2 dB and DPOAE amplitude decreased by -0.9 dB. For both groups, TEOAE amplitude decreased by approximately -0.6 dB. Eight of 12 ears with permanent threshold shift (PTS) and 10 of 13 ears with temporary threshold shift (TTS) showed TEOAE decrements or low baseline TEOAE amplitudes. Fewer TTS and PTS ears also showed DPOAE decrements, and there was never a DPOAE decrement without a corresponding TEOAE decrement or low TEOAE baseline. Some TTS ears showed permanent emission decrements. Although otoacoustic emissions show promise in detecting noise-induced inner ear changes, it is premature to use them in hearing conservation programs.

Adolescent↗
PubMed2004

Longitudinal study of changes in tibial and femoral cartilage in knee osteoarthritis.

OBJECTIVE: Despite the increasing interest in knee cartilage volume as an outcome measure in studies of osteoarthritis (OA), it is unclear what components of knee cartilage will be most useful as markers of structural change in the tibiofemoral joint. This study was undertaken to longitudinally compare changes in femoral and tibial cartilage volume in patients with OA. METHODS: One hundred seventeen patients with knee OA (58.1% women; mean +/- SD age 63.7 +/- 10.2 years) were examined. Femoral and tibial cartilage volumes (medial and lateral tibiofemoral joints) were determined from T1-weighted fat-saturated magnetic resonance images of the knee from coronal views. RESULTS: The study population was followed up for a mean +/- SD of 1.9 +/- 0.2 years. In the medial tibiofemoral joint, the mean +/- SD loss of cartilage was 0.15 +/- 0.30 ml/year for femoral cartilage and 0.10 +/- 0.25 ml/year for tibial cartilage. In the lateral tibiofemoral joint, the average loss was 0.15 +/- 0.22 and 0.12 +/- 0.16 ml/year for femoral and tibial cartilage, respectively. There was a significant correlation between the degree of loss of tibial cartilage and the degree of loss of femoral cartilage, in both tibiofemoral joints (r = 0.81, P < 0.001 at the medial tibiofemoral joint; r = 0.71, P < 0.001 at the lateral tibiofemoral joint). CONCLUSION: Longitudinal changes in tibial cartilage and those in femoral cartilage are strongly related to one another. This suggests that in tibiofemoral disease, measuring tibial cartilage alone may be adequate, given the facts that measurements of the total femoral cartilage are less reproducible and there are difficulties inherent in identifying the most appropriate component of femoral cartilage to measure.

Aged↗