Spirometric reference equations for European females and males aged 65-85 yrs.

The aim of this study was to describe spirometric reference equations for healthy never-smoking European adults aged 65-85 yrs and to compare the predicted values of this sample with those from other studies including middle-aged and/or older adults. Reference equations and normal ranges for forced expiratory volume in one second (FEV1), forced vital capacity (FVC), forced expiratory volume in six seconds (FEV6), FEV1/FVC ratio and FEV1/FEV6 ratio were derived from a healthy subgroup of 458 subjects aged 65-85 yrs. Spirometry examinations followed the 1994 American Thoracic Society recommendations and the quality of the data was continuously monitored and maintained. Reference values and lower limits of normal were derived using a piecewise polynomial model with age and height as predictors. The reference values of FEV1 and FVC from the present study were higher than those given by prediction equations from the European Community for Coal and Steel. By contrast, use of prediction equations from Caucasian-American elderly subjects (Cardiovascular Health Study) consistently overpredicted FVC and FEV1 in females by 8.5 and 2.1%, respectively. In males, equations from the Cardiovascular Health Study overpredicted FVC by 2.8%, whilst underpredicting FEV1 by 2.5%. In conclusion, these results underscore the importance of using prediction equations appropriate to the origin, age and height characteristics of the subjects being studied.     

Body plethysmographic study of specific airway resistance in a sample of healthy adults

Background and objective: sRaw (specific airway resistance) is a corrected index (Raw multiplied by thoracic gas volume) that describes airway behaviour regardless of lung volume. Normal values of sRaw in adult subjects have never been formally defined. To establish sRaw interpretation criteria and to define a range of reference values, we evaluated variability, reproducibility and reliability of sRaw measurements in a group of healthy adults. Methods: We analysed 517 subjects of both genders, aged 18–65 (group A), and to assess the reproducibility of the measurements, we investigated intra‐individual variation and potential daily and weekly sRaw rhythms in a subgroup of 18 co‐operative healthy subjects (group B). Results: In group A, there was no pattern of association between any of the considered anthropometric parameters; mean sRaw was higher in men (6.24 vs 5.95 cmH₂O s in females; P = 0.0128), but when the data were stratified by age, gender‐related differences were only found in the group aged 46–60 (males 6.45 cmH₂O s, females 6.01 cmH₂O s; P = 0.0219). In group B, there was no statistically significant, time‐dependent variation during the single tests, nor any circadian or weekly rhythm. Conclusions: sRaw is a reliable parameter; therefore, we propose that the lower and upper 95% confidence limits should be considered as reference values for adults of both genders, regardless of age. The availability of reference values may be useful in clinical practice and research.     

Prediction of metabolic and cardiopulmonary responses to maximum cycle ergometry: a randomised study.

All of the most widely-cited studies for the prediction of maximum exercise responses have utilized either volunteers or referred subjects. Therefore, selection bias, with overestimation of the reference values, is a likely consequence. In order to establish a set of predictive equations for the gas exchange, ventilatory and cardiovascular responses to maximum ramp-incremental cycle ergometry, this study prospectively evaluated 120 sedentary individuals (60 males, 60 females, aged 20-80), randomly-selected from >8,000 subjects. Regular physical activity pattern by questionnaire, body composition by anthropometry and dual energy X-ray absorptiometry (n = 75) and knee strength by isokinetic dynamometry were also assessed. Previously reported equations typically overestimated the subjects' peak oxygen uptake (p<0.05). Prediction linear equations for the main variables of clinical interest were established by backward stepwise regression analysis including: sex, age, knee extensor peak torque, bone-free lean leg mass, total and lean body mass, height, and physical activity scores. Reference intervals (95% confidence limits) were calculated: some of these values differed markedly from those formerly recommended. The results therefore might provide a more appropriate frame of reference for interpretation of the responses to symptom-limited ramp incremental cycle ergometry in sedentary subjects; i.e. those usually referred for clinical cardiopulmonary exercise tests.     

Laboratory parameters in centenarians of Italian ancestry

Studies aimed at collecting reference parameters for haematochemical analysis in the elderly are scarce and for the oldest old subjects even more rare. In order to establish the reference values for the most common laboratory text in long living individuals, we measured haematochemical parameters in >100 years old subjects and in aged subjects as control. Six hundred and two centenarians accepted to be enrolled in the study. A case history containing the complete anamnesis, clinical examinations, evaluation of the clinical cognitive and functional tests, was prepared for each centenarian. Blood samples from 120>100 years old subjects free of chronic or acute Illness (i.e. Alzheimer's disease, metabolic diseases, cardiovascular disease, stroke, neoplastic and infectious diseases) were analysed. A population of 381 healthy old subjects (age range 65-85 years old), recruited in the same geographic areas and with the same clinical characteristic of the health centenarians, was utilized as control. Significant differences were observed for blood glucose, ALT, cholesterol and platelet levels, reduced in centenarians respect to the old subjects, whereas blood urea nitrogen levels were found significantly increased in centenarians. In conclusion, reference values of the healthy adults can generally been utilized also for the healthy oldest old group, with the notable exception of the above mentioned laboratory parameters that appear to be modified in long living subjects.     

Reference values for spirometry,including vital capacity,in Japanese adults calculated with the LMS method and compared with previous values

BackgroundReference values for lung function tests should be periodically updated because of birth cohort effects and improved technology. This study updates the spirometric reference values, including vital capacity (VC), for Japanese adults and compares the new reference values with previous Japanese reference values.MethodsSpirometric data from healthy non-smokers (20,341 individuals aged 17–95 years, 67% females) were collected from 12 centers across Japan, and reference equations were derived using the LMS method. This method incorporates modeling skewness (lambda: L), mean (mu: M), and coefficient of variation (sigma: S), which are functions of sex, age, and height. In addition, the age-specific lower limits of normal (LLN) were calculated.ResultsSpirometric reference values for the 17–95-year age range and the age-dependent LLN for Japanese adults were derived. The new reference values for FEV₁ in males are smaller, while those for VC and FVC in middle age and elderly males and those for FEV₁, VC, and FVC in females are larger than the previous values. The LLN of the FEV₁/FVC for females is larger than previous values. The FVC is significantly smaller than the VC in the elderly.ConclusionsThe new reference values faithfully reflect spirometric indices and provide an age-specific LLN for the 17–95-year age range, enabling improved diagnostic accuracy. Compared with previous prediction equations, they more accurately reflect the transition in pulmonary function during young adulthood. In elderly subjects, the FVC reference values are not interchangeable with the VC values.     

Comparison of spirometric reference values

Lung-function reference values play a vital role in the management of respiratory disorders. There are many proposed reference equations for pediatric spirometry. Recently, spirometric reference equations were proposed, using data from people aged 8-80 years living in the US compiled by the third National Health and Nutrition Examination Survey. Our objective was to compare the predictive value of wider age-range reference equations to established pediatric reference equations for the pediatric population. Spirometry, height, and weight were obtained from 70 normal children aged 6-18 years. The difference between measured and predicted values as suggested by different reference equations was compared. Predicted values from general equations significantly differed from those generated from pediatric equations and from measured values in this population. The difference between measured and predicted values from the wider age-range equations varied between 7-16% for forced expired volume in 1 sec (FEV1) and forced vital capacity (FVC). The difference between measured and predicted values for the pediatric equations varied between 1-4%. Although wider age-range equations provide continuity through age ranges, their predictive accuracy may be low in the pediatric age group, especially for the youngest, smallest children. Extrapolating reference equations beyond the age range of subjects used to generate then is not recommended.     

Incidence of disability in housebound elderly people in a rural community in Japan

Background:   Although being housebound is acknowledged conceptually as a risk factor for disability and social isolation, there has been little epidemiologic research on housebound status. This study aimed to explore whether being housebound is a risk factor for disability and whether a low level of social contact increases that risk in elderly persons.
Methods:   A questionnaire pertaining to demographic characteristics was administered to 2932 community-dwelling elderly persons (aged 65 years and older) in October 2000. There were 2459 responses, and 2180 respondents were independently performing activities of daily living. Of these, 2046 were followed up until March 2003. These 2046 people became the subjects of our analysis. At the end of the follow-up period, the 2046 subjects were assessed for disability.
Results:   Overall, 7.5% of the subjects were housebound at baseline, and about half of these were able to leave the house unassisted, seldom did so but had social contact. At the end of the follow-up period, 12.7% of subjects were identified as disabled. The incidence of disability was higher in housebound than in non-housebound subjects aged less than 85 years but did not differ significantly among subjects aged more than 85 years. Levels of disability were higher in all housebound subjects groups than in non-housebound subjects. Subjects without social contact exhibited a higher incidence of disability than others, although the difference was not statistically significant.
Conclusion:   Being housebound appears to be a risk factor for disability in community-dwelling individuals aged 65–85 years who are living independently, but a low level of social contact was not proved to be an additional risk factor for disability among housebound elderly persons.     

Prediction equations for pulmonary function values in healthy young Iranians aged 8-18 years

OBJECTIVE: Pulmonary function test (PFT) variables are dependent on height, age and gender. In addition, there is evidence of PFT variation in different ethnic groups. Prediction equations for PFT from a healthy, non-smoking, urban young population in the city of Mashhad (north-east Iran) have been derived. METHODOLOGY: Prediction equations for normal pulmonary function were derived from 336 healthy, non-smoking subjects, including 187 males (height 103-188.5 cm) and 149 females (height 104-183 cm) aged 8-18 years. The subjects underwent measurement of spirometric flow and volume. The following variables were measured: FVC, FEV1, maximal mid-expiratory flow (MMEF), PEF, maximal expiratory flow at 75, 50 and 25% of the FVC (MEF75, MEF50, and MEF25, respectively), tidal volume (VT), inspiratory reserve volume (IRV), expiratory reserve volume (ERV), inspiratory capacity (IC), and vital capacity (VC). Regression analysis using height and age as independent variables was applied to provide predicted values for both genders. RESULTS: There were positive correlations for each pulmonary function variable with height and age. The largest positive correlations were found for FEV1 with height and age, in both genders. Comparison of PFT variables derived from the equations obtained in the present study showed significant differences to those calculated from several previously published equations (P < 0.001 for most variables). For example, the values of FVC and FEV1 derived from the equations obtained in the present study were 2.83 +/- 0.99 and 2.50 +/- 0.89 for males, and 2.41 +/- 0.54 and 2.19 +/- 0.53 for females, while the values derived from the equations of the European Community for Steel and Coal study were 3.12 +/- 1.06 and 2.62 +/- 0.89 for males and 2.79 +/- 0.67 and 3.35 +/- 0.57 for females, respectively. CONCLUSIONS: A set of PFT reference values and prediction equations for both genders has been derived using a relatively large, healthy, non-smoking Iranian young population, and has generated results that differ from several other prediction equations.     

Morbidity, disability, and health status of black American elderly: a new look at the oldest-old.

There are over 2.5 million black Americans aged 65 and over living in the United States today, including some 258,000 persons aged 85 years and over. The post-World War II baby boom within the US black population should ensure that the numbers of persons aged 65 and over will increase into the 21st Century. If present trends continue, it is projected that the current population of black elders will also age. This means that the numbers of black persons aged 85 and over will also increase. Data from both national surveys and population-based community studies concerning the health and well-being of black elders are now becoming available. This report presents information concerning self-reported health status, chronic disease prevalence, disease-risk-factor prevalence, measures of physical functioning, and nursing home utilization rates for age groups within the black population aged 65 years and over. The availability of such data should lead to the development of targeted interventions designed to lessen impairment and prolong independent living.     

Renal function and delirium in older fracture patients: different information from different formulas?

Objectivesthe association between renal function and delirium has not been investigated in older fracture patients. Creatinine is frequently low in these subjects, which may influence the association between delirium and renal function as estimated with creatinine-based formulas. Cystatin C could be a more reliable filtration marker in these patients.Aimto confirm the association between renal function and delirium in older fracture patients comparing creatinine- and cystatin-based estimated glomerular filtration rate (eGFR)Methodspatients aged 65+ requiring surgery for traumatic bone fractures were included. Six equations were used to calculate eGFR, based on serum creatinine and/or cystatin C obtained within 24 h of admission: Modification of Diet in Renal Disease (MDRD), Chronic Kidney Disease Epidemiology (CKD-EPI_cr, CKD-EPI_cys, CKD-EPI_cr-cys) and Berlin Initiative Study equations (BIS-1, BIS-2). Delirium was identified with a chart-based method.Results571 patients (mean age 83) were enrolled. Delirium occurred in the 34% and was associated with a lower eGFR regardless of the equation used. In a multivariable model, the association between moderate renal impairment (eGFR 30–60 ml/min/1.73 m²) and delirium remained significant in patients aged 75–84 and only when estimated with cystatin-based or BIS-1 equations. Only dementia was significantly associated with delirium in subjects 85+.Conclusionsin older fracture patients, moderate renal impairment was independently associated with delirium only among subjects aged 75–84, when eGFR was estimated with cystatin-based or BIS 1 equations, and not with the most commonly used equations (MDRD, CKD-EPI_cr).     

Reference values of diffusing capacity of non-smoking Chinese in Hong Kong

BACKGROUND AND OBJECTIVE: This study was conducted to define normal reference values and lower limits of normal (LLN) for single-breath carbon monoxide diffusing capacity (DLco) and DLco per unit of alveolar volume (Kco) for Chinese adults in Hong Kong. METHODS: Healthy non-smoking men and women aged 18-80 years were recruited by random digit dialing. DLco and Kco were measured according to American Thoracic Society standards. Reference equations were obtained by multiple linear regression; LLN were derived by distribution-free method for estimation of age-related centiles. RESULTS: Tests from 568 subjects (259 men, 309 women) were analysed. DLco declined with age in both genders, and increased with height and the interaction term of height and age in men and women, respectively. Considering Hb values did not improve the reference equations. Kco declined with age and increased with weight in both genders, while height and its interaction term with age were additional determinants in women. The reference DLco was lower than some Caucasian values, and was only explained partially by a smaller body size and alveolar volume in Chinese. The distribution-free method yielded better overall approximation to the fifth percentile compared with the traditional method of determining LLN. CONCLUSIONS: The equations for reference values and LLN of diffusing capacity derived in this study are of clinical relevance to Chinese subjects.     

A re-validation of the Rivermead ADL scale for elderly patients with stroke

The Rivermead ADL scale was developed for assessing activities of daily living in stroke patients but was not validated for elderly subjects. This study was designed to validate the scale for patients aged over 64 years. A series of 150 stroke patients was assessed on the scale, of whom 103 were aged over 64 years. The coefficients of reproducibility and 'scalability' were within acceptable limits both for patients aged under 65 and over 64 years. A revised order of assessment is suggested based on the order of difficulty of items. The two original household scales were combined to give an overall household scale which was validated as a unidimensional Guttman scale.     

Peak expiratory flow in normal healthy Japanese adults: Comparisons with values reported in other races

BackgroundWe investigated the relationship between peak expiratory flow (PEF), age and standing height in 2785 Japanese volunteers (1047 males), aged 15–84 years, who had never smoked and who satisfied other strict criteria of normality. Many reports of regression equations for PEF by country and ethnicity are prepared using Wright or mini-Wright PEF meters, which have been calibrated by human subjects. Yet, no study has been performed in any country to determine the reference values of PEF on the American Thoracic Society (ATS) scale, which is calibrated by a computerdriven mechanical pump.MethodsPeak expiratory flow was measured with mini-Wright meters calibrated on the Wright scale. All subjects were taught how to perform a forced expiratory maneuver: the highest of three PEF values was recorded and standing height was measured. The Miles equation was used to convert mini-Wright PEF values (traditional scale) to values using the new ‘mechanical’ PEF, which the ATS has recommended (ATS scale). In the analysis of the data, a model based on age, age squared and age cubed was used to derive curvilinear regression equations for PEF on age and standing height for each sex.ResultsThere was adequate representation of subjects of each sex at all ages to 74 years. Curves plotted from the regression equations rose during adolescence and early adulthood, reached maximum values at 35 years in males and 40 years in females and then declined in an approximately linear manner. For both sexes, standing height fell progressively with increasing age.ConclusionsFrom the regression equations, predicted values of PEF can be derived for any Japanese adult aged 15–74 years. We were able to obtain predicted equations for PEF in normal Japanese adults using both the Wright and ATS scales. Direct comparison of our regressions with those reported in other populations was limited by differences in methodology and analysis. In comparable studies of Chinese and Indian populations, the PEF values in those studies were appreciably lower than ours. Our regressions were remarkably similar to those reported in a study of British subjects that used virtually identical entry criteria and methods.     

Hazardous drinking: prevalence and associations in the Finnish general population

Background:  Hazardous drinking, defined as consuming alcohol on a risky level and not meeting the diagnostic criteria of alcohol use disorders (AUDs), has been suggested for a new complementary nondependence diagnosis. This study aimed to investigate the prevalence and associations of hazardous drinking in comparison to AUDs, moderate drinking, and abstinence.
Methods:  A national representative sample of Finns was examined in the Health 2000 Survey. For 4477 subjects aged 30 to 64 years (76%, 2341 females), both the quantity frequency data about alcohol consumption and Composite International Diagnostic Interview (CIDI) data concerning AUD diagnoses were available. The nationally recommended limits for hazardous dinking were used (males: 24 drinks, females: 16 drinks/wk). Logistic regression models were used to analyze associations.
Results:  The prevalence of hazardous drinking was 5.8%. Hazardous drinking was more prevalent among males than females (8.5% vs. 3.1%). It was most prevalent among the subjects aged 40 to 49 years (7.3%), divorced or separated (8.3%), unemployed (8.2%) and subjects living in the southern (Helsinki) region (7.5%). AUDs versus hazardous drinking were more likely to be in males versus females and in the unemployed versus employed. Subjects aged 40 and over had higher odds for hazardous drinking versus AUDs. The odds for hazardous versus moderate drinking were higher for males versus females (adjusted odds ratio = 3.24), for subjects aged over 40 years, unemployed versus employed and cohabiting, divorced/separated or unmarried subjects versus married subjects.
Conclusion:  The high prevalence of hazardous drinking makes it an important public health concern. Hazardous drinkers have different sociodemographic characteristics as compared to people in other alcohol use categories.     

Prediction equations for lung function in healthy, life time never-smoking Malaysian population

Several equations have been used to predict lung function standard results for different populations. It is important lung function evaluations use appropriate standards for the study population. The objective of this study was to develop a prediction equation for lung function test results for the Malaysian population. Spirometry was performed among 5,708 subjects and 1,483 healthy, lifetime never smoked subjects (386 males and 1,097 females). Prediction equations were derived for both men and women for FVC and FEV1 results. The equations were validated on new subjects (n = 532, 222 males and 310 females) who met the same inclusion and exclusion criteria as the main cohort. There was a positive correlation between the measured values and the values derived from the new prediction equations (0.62 for FEV1 and between 0.66 and 0.67 for FVC; both p < 0.05) for both men and women with a smaller bias and limit of agreement compared to the published reference equations of ECCS, Knudson, Crapo and NHANES III. The reference equations derived from local spirometry data were more appropriate than generally used equations based on data from previous studies in different population.     

Reference values for alveolar membrane diffusion capacity and pulmonary capillary blood volume.

The reference values for diffusion capacity of the alveolar capillary membrane (Tm,CO) and pulmonary capillary volume (Qc) are scarce, while the standard deviations of the equations are large. New equations and residual standard deviations (RSDs) were determined in a sample of healthy subjects. Tm,CO and Qc values were measured in 117 (72 females, 45 males) nonsmoking healthy subjects. The carbon monoxide transfer factor (TL,CO) was determined when the volunteer was breathing room air and subsequently, when the volunteer was breathing 100% oxygen. From these data, Tm,CO and Qc values were calculated. The females' TL,CO was 3.15 mmol x min(-1) x kPa(-1) lower than the males', apparently caused by lower female lung volume. Tm,CO and Qc were lower in females, but correction for lung volume eliminated this difference. Qc(-1) reference equations for females and males, respectively, are 4.375 x 10(-2) - 1.085 x l0(-2) x height and 4.455 x 10(-2) -1.085 x 10(-2) x height (RSD for both sexes: 2.544 x 10(-3)). Tm,CO(-1) reference equations for females and males, respectively, are 0.111+3.304 x 10(-4) x age-4.753 x 10(-2) x height and 0.127+3.304 x 10(-4) x age-4.753 x 10(-2) x height (RSD for both sexes: 1.085 x 10(-2)). The general character of these equations complies with earlier publications, the only difference being that the RSDs are 1.18-2.76 times lower. New reference equations for diffusion capacity of the alveolar capillary membrane and pulmonary capillary volume are available with considerably smaller residual standard deviations.     

Reference values for pulmonary function in Asian Indians living in the United States

OBJECTIVE: To establish reference values for pulmonary function in the Asian-Indian population living in the United States. DESIGN: Five-year cross-sectional study of pulmonary function in healthy adult Asian Indians living in the United States, using American Thoracic Society guidelines for measuring pulmonary function. SETTING: Measurement of pulmonary function in healthy nonsmoking Asian Indians in a pulmonary function laboratory or at festivals, picnics, and ceremonies where subjects could be conveniently recruited. PARTICIPANTS: Four hundred sixty subjects from a population of Asian Indians residing in the Chicago metropolitan area. MEASUREMENTS: Spirometry was performed in all subjects with measurements of FEV(1), FVC, and forced expiratory flow between 25% and 75% of vital capacity (FEF(25-75)). Lung volumes were measured in eighty subjects. Prediction equations for FEV(1), FVC, and FEF(25-75) were derived using multiple regression analysis. RESULTS: Three hundred sixty-three subjects (226 men and 137 women) met the inclusion criteria. Spirometric values derived from our prediction equations, when compared to the values for whites from the selected studies in the literature, showed FVC to be 20 to 24% lower in men and 25 to 28% lower in women. FEV(1) was 16 to 23% lower in men and 20 to 26% lower in women. Differences were not quite as large when compared to values from African Americans and other studies on Asians. CONCLUSIONS: We provide reference values for pulmonary function in nonsmoking Asian Indians living in the United States. These reference values should be used for evaluation of pulmonary function in this population.     

Spirometric reference equations for older adults

The objective of this study was to develop spirometric reference equations for healthy, never-smoking, older adults. It was designed as a cross-sectional observational study consisting of 1510 Seventh Day Adventists, ages 43-79 years enrolled in a study of health effects of air pollutants. Individuals were excluded from the reference group (n = 565) for a history of current respiratory illness, smoking, or chronic respiratory disease, and for a number of 'non-respiratory' conditions which were observed in these data to be related to lower values of FEV1. Gender-specific reference equations were developed for the entire reference group and for a subset above 65 years of age (n = 312). Controlling for height and age, lung function was found to be positively related to the difference between armspan and height, and in males was found to be quadratically related to age. The predicted values for this population generally fell within the range of those of other population groups containing large numbers of adults over the age of 65 years. Individuals with lung function below the 5th percentile in this sample, however, could not be reliably identified by using the lower limits of normal predictions commonly used in North America and Europe.     

Differentials in mortality up to 20 years after baseline interview among older people in East London and Essex

Objective: to identify socio-psychological predictors of mortalityduring a 20-year follow-up period among people aged 65 to <85and 85+ at baseline interview. Study design and setting: elderly people living at home in EastLondon and mid-Essex, who responded to surveys of successfulsurvival in older age in the late 1980s; their mortality wastraced through the National Health Central Registry. Results: adjusted analyses show that, as expected, the hazardrate for mortality over a 20-year follow-up was reduced foryounger respondents and increased for less functionally ablerespondents. The hazard ratio for males was almost one and ahalf times that of females. The hazard rate was also reducedwith each categorical increase in life satisfaction and wasconsistently reduced for those who undertook crafts, socialvisiting and activities regularly. There was some variationby age and sex. Conclusion: the results show that social participation is associatedwith lower risks of death, particularly among people aged 65to <85, and that life satisfaction is also protective, particularlyamong females and people aged 85+, even when health status andsocio-demographic circumstances are controlled. The study thusprovides support for the hypothesised influence of social participationand subjective well-being on survival in older age.     

Body composition in elderly people. II. Comparison of measured and predicted body composition in healthy elderly subjects

The predictive values of the equations of Moore et al. and Hume and Weyers and the measured values of body composition were compared in healthy, carefully selected aged and young subjects of both sexes. In the case of young subjects, these prediction equations seem to be adequate, even if this could not be affirmed with certainty by our results. The equations of Moore et al. were found not to be adequate for elderly males, while they were only suitable for the determination of intracellular components in elderly females.