The assessment of biological age: a report from the Department of Environment Study

Difference between the biologic and chronologic age as an individualized indicator for the skincare intensity selection: skin cell profile and age difference studies

Background

The present research addresses the issue of skin aging and corresponding skin treatment individualization. Particular research question was on the development of a simplified criterion supporting patient-specific decisions about the necessity and intensity of skin treatment. Basing on published results and a wide pool of our own experimental data, a hypothesis is formulated that a difference between biologic and chronologic age can be used as a powerful indicator of skin aging.

Methods

In the present paper, we report the results of studies with 80 volunteers between 15 and 65 years of age linking skin cell profile parameters to biologic and chronologic age. Biologic age was calculated using the empirical expressions based on the forced vital lung capacity, systolic blood pressure, urea concentration, and blood cholesterol level. Epidermis and derma cellular structures were studied using skin biopsy samples taken from the gluteal region.

Results

The present study supports the conclusion that biologic and chronologic age difference is changing in the progress of life. Our studies are showing that time point when calculated biologic age becomes equal to the chronologic one reflecting the onset of specific changes in the age dependencies of experimentally measured skin cell profile parameters. Thus, it is feasible that a difference between chronologic and individually assessed biologic age indeed reflects the process of skin aging.

Conclusions

With all reservations to the relatively small number of study participants, it seems feasible that a difference between biologic and chronologic age can be used as an indicator of skin aging. Additional research linking blood immune profile and skin topography to the difference of biologic and chronologic age (reported in the following paper) provides further support for the formulated hypotheses. So, a difference between calculated biologic age and chronologic age can be used as an individualized criterion supporting decisions on skin treatment strategies. Further research involving larger numbers of participants aimed at optimizing the expressions for calculating biologic age could lead to reliable and easily available express criterion supporting the decision for the individualized skin treatment.

Adverse social factors predict early ageing in middle-aged men and women: the Ebeltoft Health Study, Denmark

Aims: This study examined whether adverse social factors are associated with an increased rate of biological ageing in middle-aged subjects. Methods: The authors investigated five markers of biological ageing in 690 subjects followed for five years in Ebeltoft, Denmark. Mean age at baseline was 40 years (range 30 - 50 years). These markers included repeated measures of pulse pressure, lung function, hearing, physical work capacity and a cardiovascular risk score. A z-score was calculated based on a factor analysis of the five markers used. The relative biological age was finally calculated in relation to chronological age in subgroups of different social class (occupation, educational level) and marital status, at baseline and after follow-up. Results: Men and women from a higher social class appeared to be biologically younger than corresponding subjects from a lower social class (p<0.001). This difference was still evident after 5 years of follow-up (p<0.01) for men and women of different occupations and for women of different educational levels (p<0.01). Married/cohabiting men were biologically younger than single men and this difference increased during the follow-up period in that the difference between groups at five-year follow-up was significant (p<0.05). Conclusions: Middle-aged men and women from a higher social class showed signs of being biologically younger than their corresponding chronological age, while the opposite was found for men and women of lower social class. This discrepancy was still evident after five years of follow-up, and even tended to increase for single men. Differential ageing may thus be an important biological aspect of differences in health according to social class.

Early ageing in middle-aged men is associated with adverse social factors and increased mortality risk: The Malmö Preventive Project

Aims: This study examined whether middle-aged men exhibiting markers of early ageing showed a different pattern of social factors, lifestyle, and biological variables compared with controls, and whether early ageing was associated with an increased mortality risk. Subjects and methods: We used a subgroup of 5,722 middle-aged men (mean age 47 years), investigated twice, from the Malmö Preventive Project (MPP), a screening programme attended by a total of 22,444 men between 1974 and 1992. Markers of biological ageing, such as decreased lung function, increased pulse pressure, and decreased height, were used to identify early aged subjects and a control group. These were followed up by use of local and national registers for a mean of 22 years. Cox's proportional regression was used to estimate multivariate relative risks (RR) for mortality with 95% confidence intervals (CI). Results: Men with early ageing were more often smokers, living alone, or less likely to be non-manual workers than control subjects. These men also had an increased age-adjusted mortality relative risk, RR 1.29 (95% CI 1.10—1.52). After adjustment for social and lifestyle factor there was still a significant difference in mortality between the two groups, RR 1.19 (95% CI 1.00—1.42). Conclusion: Early biological ageing in middle-aged men is associated with an increased mortality risk during long-term follow-up that cannot be fully explained by social background characteristics or adverse lifestyle.

Smokers' hair: Does smoking cause premature hair graying?

AIMS

To determine if there is a significant association between premature hair graying and cigarette smoking.

MATERIALS AND METHODS

A cross-sectional observational study was conducted in a nonclinical setting on 207 participants on August 24 until 25, 2010. Participants were classified into two groups [premature hair graying (PHG) and normal hair graying]. PHG was defined as the first appearance of gray hair before the age of 30. Data were collected using an interview questionnaire and measurements of body mass index, waist circumference, fasting blood glucose and blood pressure. Collected data were statistically analyzed using SPSS 16, Chicago, IL.

RESULTS

Of the 207 subjects, 104 (50.2%) had first appearance of gray hair before the age of 30 (PHG group) while the other 103 (49.8%) were considered normal hair graying group. The prevalence of smokers in the "PHG" group was higher (40.2% vs. 24.7%, P = 0.031). Smokers had earlier onset of hair graying (smokers: 31 (7.4) vs. nonsmokers: 34 (8.6), P = 0.034). Using multiple logistic regression with conditional likelihood, smokers were two and half times (95% CI: 1.5-4.6) more prone to develop PHG.

CONCLUSION

This study suggests that there is a significant relation (with adjusted odds ratio of two and half) between onset of gray hair before the age of 30 and cigarette smoking.

Visco-elastic response of human skin and aging

The changes in visco-elastic properties of skin belong to the most conspicuous manifestations of cutaneous aging. In spite of apparent simplicity, the measurement of mechanical parameters of skin in vivo presents both theoretical and practical problems. Reproducibility, standardization, duration of measurement, discomfort for experimental subjects are the main complications. Measurement and analysis of transient deformation response to pressure stress provides theoretically consistent and practically applicable methodology.

EXPERIMENT

The transient deformation response of skin was measured in two groups consisting of 15 healthy men and 17 healthy women. The range of age interval was 20 to 58 years. The deformation response was measured as reaction of skin on sudden change of pressure stress between two levels of loading on skin surface.

RESULTS

Transient response of human skin consists of sum of two exponential curves. A "rapid" exponential curve has time constant typically of order 10 ms, while "slow" exponential curve has a time constant of order 0.1 to 1s. Both time constants increase with chronological age. Time for drop of deformation on 12.5% of full deformation proved to be a simple and sensitive criterion of skin aging, with strong correlation with chronological age. Main advantage of the method: Measurement is quantitative and reproducible. Procedure is easy to repeat. Its average duration is approx. 2 minutes and it does not represent any discomfort for test subjects.

Indicators of "healthy aging" in older women (65-69 years of age). A data-mining approach based on prediction of long-term survival

Background

Prediction of long-term survival in healthy adults requires recognition of features that serve as early indicators of successful aging. The aims of this study were to identify predictors of long-term survival in older women and to develop a multivariable model based upon longitudinal data from the Study of Osteoporotic Fractures (SOF).

Methods

We considered only the youngest subjects (n = 4,097) enrolled in the SOF cohort (65 to 69 years of age) and excluded older SOF subjects more likely to exhibit a "frail" phenotype. A total of 377 phenotypic measures were screened to determine which were of most value for prediction of long-term (19-year) survival. Prognostic capacity of individual predictors, and combinations of predictors, was evaluated using a cross-validation criterion with prediction accuracy assessed according to time-specific AUC statistics.

Results

Visual contrast sensitivity score was among the top 5 individual predictors relative to all 377 variables evaluated (mean AUC = 0.570). A 13-variable model with strong predictive performance was generated using a forward search strategy (mean AUC = 0.673). Variables within this model included a measure of physical function, smoking and diabetes status, self-reported health, contrast sensitivity, and functional status indices reflecting cumulative number of daily living impairments (HR ≥ 0.879 or RH ≤ 1.131; P < 0.001). We evaluated this model and show that it predicts long-term survival among subjects assigned differing causes of death (e.g., cancer, cardiovascular disease; P < 0.01). For an average follow-up time of 20 years, output from the model was associated with multiple outcomes among survivors, such as tests of cognitive function, geriatric depression, number of daily living impairments and grip strength (P < 0.03).

Conclusions

The multivariate model we developed characterizes a "healthy aging" phenotype based upon an integration of measures that together reflect multiple dimensions of an aging adult (65-69 years of age). Age-sensitive components of this model may be of value as biomarkers in human studies that evaluate anti-aging interventions. Our methodology could be applied to data from other longitudinal cohorts to generalize these findings, identify additional predictors of long-term survival, and to further develop the "healthy aging" concept.

Experience with sorafenib and the elderly patient

Renal cell carcinoma primarily affects older individuals. Approximately half of all new renal cell carcinoma diagnoses are made in persons 65 years of age or older. Devising a treatment plan for the elderly patient population requires special consideration. Age-related physiological, cognitive, and social characteristics of elderly patients may influence each stage of patient care. Until recently, treatment options were limited for elderly patients with renal cell carcinoma. Sorafenib is the first multikinase inhibitor approved for use in renal cell carcinoma in the United States and Europe. In the phase III Treatment Approaches in Renal Cell Cancer Global Evaluation Trial, sorafenib significantly extended progression-free survival in patients with advanced renal cell carcinoma, regardless of age. Incidence rates of adverse events were not significantly higher in elderly patients receiving sorafenib than in younger patients. Thus, sorafenib represents an important treatment option for elderly patients with renal cell carcinoma. This report describes particular considerations for physicians to be aware of when choosing a treatment regimen for their elderly patients with renal cell carcinoma and offers recommendations on how to integrate specific management strategies into clinical practice that will optimize the use of sorafenib in the elderly. The strategies focus on patient selection, assessment of quality of life, management of adverse events, and appropriate dose modifications. The goal of these recommendations is to maximize the clinical benefit of sorafenib in the elderly patient population through appropriate use.

Increased abdominal obesity, adverse psychosocial factors and shorter telomere length in subjects reporting early ageing; the MONICA Northern Sweden Study

BACKGROUND

The rate of biological ageing is individual and represents the steady decrease in physiological and mental functions. Adverse social factors have been shown to influence this process. Self-perceived early ageing (SEA) might be a useful indicator of early biological ageing and increased mortality risk. The aim of this population-based study was to identify markers of SEA, including telomere length.

METHODS

We studied 1502 subjects (744 men, 758 women) from Northern Sweden. These subjects underwent a physical examination, blood sampling (including telomere length) and completed a self-administered questionnaire about their subjective age, social situation, lifestyle, and self-rated health (SRH). Age- and SRH-adjusted statistical analyses were made comparing SEA subjects with same-sex controls.

RESULTS

In all, 7.9% of men and 12.1% of women reported SEA. These subjects had significantly (p<0.0001) wider waist circumference and higher body mass index than controls. SEA men showed higher fasting glucose and SEA women showed higher total cholesterol levels than controls (p=0.020 and p=0.015, respectively). In addition, SEA women more often reported infrequent physical exercise (p=0.006), mental problems (p=0.064) and worse SRH (p=0.001) than controls. In a random sub-sample, telomere length was significantly shorter in SEA subjects (n=139) than controls (n=301; p=0.02), but not after full adjustment for BMI.

CONCLUSIONS

Self-perceived early ageing is not uncommon and is associated with abdominal obesity, poor self-rated health, lower education, and shorter telomere length. This could link adverse social factors with features of the metabolic syndrome as well as with early biological ageing, of importance for targeting preventive programmes.

Ageing and vascular ageing

There is an age related decline in various physiological processes. Vascular ageing is associated with changes in the mechanical and the structural properties of the vascular wall, which leads to the loss of arterial elasticity and reduced arterial compliance. Arterial compliance can be measured by different parameters like pulse wave velocity, augmentation index, and systemic arterial compliance. There is evidence that arterial compliance is reduced in disease states such as hypertension, diabetes, and end stage renal failure. Changes in arterial compliance can be present before the clinical manifestation of cardiovascular disease. Pharmacological and non-pharmacological measures have been shown to improve arterial compliance. Arterial compliance may constitute an early cardiovascular risk marker and may be useful in assessing the effects of drugs on the cardiovascular system. Pharmacogenetics and genetics of arterial compliance in the future will improve our knowledge and understanding about vascular ageing.

Disentangling the genetic determinants of human aging: biological age as an alternative to the use of survival measures

The choice of a phenotype is critical for the study of a complex genetically regulated process, such as aging. To date, most of the twin and family studies have focused on broad survival measures, primarily age at death or exceptional longevity. However, on the basis of recent studies of twins and families, biological age has also been shown to have a strong genetic component, with heritability estimates ranging from 27% to 57%. The aim of this review is twofold: first, to summarize growing consensus on reliable methods of biological age assessment, and second, to demonstrate validity of this phenotype for research in the genetics of aging in humans.

Why do some people look older than they should?

BACKGROUND

As a component of studies on biological age, the age of subjects from their appearance (perceived age) was estimated.

OBJECTIVE

To determine the factors associated with looking older.

METHODS

Cross sectional study of London civil servants (318 men, 129 women) in the Department of the Environment study. Perceived age was recorded by an observer and the difference between this age and chronological age was analysed according to 20 different variables.

RESULTS

Men had an average perceived age of 0.37 years older than their actual age and women a perceived age of 0.54 years younger. In men, looking older was related to greying of the hair, grade of arcus senilis, and grade of baldness. Less expected, looking older was positively related to total serum cholesterol (p=0.03) and blood haemoglobin (p<0.01). In women, looking older was related to greying of the hair, positively to blood erythrocyte sedimentation rate (ESR), and negatively to serum bilirubin (p=0.01). Looking older was not related to alcohol consumption, employment grade, serum high density lipoprotein cholesterol, glucose, albumin, and calcium in either sex.

CONCLUSION

The relationships between looking older and total cholesterol and haemoglobin in men and ESR and bilirubin in women, require further investigation.

Vascular compliance as a measure of biological age

OBJECTIVES

To determine the measure of vascular compliance most closely related to age.

DESIGN

A review of 22 studies relating aortic compliance to age and a discussion of other factors related to vascular compliance.

MEASUREMENTS

Aortic compliance, elastic modulus, postmortem aortic changes, pulse wave velocity in the aorta, common carotid, lower limb and upper limb.

RESULTS

1. Aortic compliance and carotid artery compliance is closely related to age; 2. Compliance in the peripheral arteries, in 16 reports, appears less closely related to age; 3. There is evidence that aortic compliance is related to hypertension, cardiac function, and left ventricular hypertrophy and can be increased by exercise, hormonal therapy, antioxidant and antihypertensive treatment; and 4. Vascular compliance is more closely related to chronological age than other measures such as skin inelasticity, greying of hair, baldness etc.

CONCLUSIONS

Because of the close relationship between aortic and carotid compliance and chronological age, deviation from the age-predicted norm (biological age) may prove to be a good predictor of cardiovascular pathology.

A strategy for identifying biomarkers of aging: further evaluation of hematology and blood chemistry data from a calorie restriction study in rhesus monkeys

We examined a dataset derived from a battery of hematology and blood chemistry tests to identify candidate biomarkers of aging in a sample of 33 male rhesus monkeys (Macaca mulatta) ranging in age from 4-27 years. About half this sample comprised an experimental group subjected to 30% calorie restriction for six to seven years compared to the control group fed the same nutritionally fortified diet to approximate ad lib levels. Variables that met the following criteria were selected: (1) longitudinal change within the cohorts of control monkeys; (2) cross-sectional correlation with age across the adult lifespan in the control group; (3) stability of individual differences within all groups; and (4) no obvious redundancy with other selected variables. Five variables emerged from this step-wise selection, including the percentage lymphocytes, and serum levels of alkaline phosphatase, albumin, creatinine, and calcium. These variables were then submitted to a principal component analysis, which yielded a single component accounting for about 58% of the total variance. Based on this marked degree of covariance, these candidate biomarkers of aging could be combined into a biological age score (BAS) for the control and experimental groups. When chronological age was regressed onto BAS, the slopes of the control and experimental groups could be compared. Although a trend toward a slower aging rate in calorie-restricted monkeys was apparent, this analysis did not detect a statistically significant difference in the rate of aging between these groups estimated by this index. Despite this result, a logical strategy was confirmed for expanding the search for candidate biomarkers of aging to apply to this and to other studies assessing interventions that purport to affect the rate of aging in long-lived species.

Age differences in biochemical and hematological measures during middle age

Biochemical and hematological measures possibly associated with ageing were measured on a single occasion in 3402 male and 2152 female London Civil Servants aged from 35 to 59 years of age. These included erythrocyte sedimentation rate (ESR), blood hemoglobin and serum albumin, calcium, bilirubin, creatinine, urea, urate, high density lipoprotein (HDL), and total cholesterol. Independently and positively related to age were ESR with an estimated 47% 'increase' in men over the 15 years between ages 40 to 55 and a 40% increase in women; serum urea had a 6%/15-year increase in men and 20% in women; total cholesterol had a 6%/15-year increase in men and 18% in women; serum creatinine 'increased' by 2%/15-years in men and 5% in women. In women, urate, HDL cholesterol and hemoglobin increased with age group. Negatively related to age was serum bilirubin in both sexes (8% and 6% 'fall'/15-years in men and women respectively). Serum albumin and calcium fell with age group in men. The sexes differed in their relationship to aging for total cholesterol and HDL cholesterol (greater increase in women), serum calcium (small decrease in men and small increase in women), urate and hemoglobin (increases in women but not men). Urea increased more in women than men, and albumin decreased more in men than women (p < 0.001 for all comparisons with the exception of HDL cholesterol, p < 0.01). Changes during the menopause were thought to explain some of these findings.