Managing Aging Men in Asia: a Strategic Approach
ABSTRACT
We have established a comprehensive diagnostic paradigm for the management of aging men which seeks to evaluate the varions determinants of the aging process in five major health areas: cardio- health, bone health, sex health, general health and endocrine state. This paradigm appears to be useful for the management of the problem of aging in our local population. It could be used for the management of individuals as well as for population research. When combined with the establishment of evidence-based management modalities, it will provide a useful tool for the holistic management of aging in Asia.
Key words: AGING MEN, ASIA, MANAGEMENT
INTRODUCTION
The advent of anti-aging medicine in Asia and the aggressive push of non-evidence based practices have left many of the public confused and bewildered as to what is good medicine and what is bogus1. There is an urgent need for the medical fraternity to provide a comprehensive understanding of the aging process and how it impacts on the health of the average aging person, and, thence, to establish appropriate and evidence-based management modalities to address the increasing public concern about the problem of aging.
The study of aging is a relatively new science, and is not the exclusive domain of any subspecialty of medicine or paramedical discipline. Hence, it would be expedient to adopt a holistic approach by incorporating biomedical, social, economic and behavioral aspects into the management of aging2-5.
The key to establishing a holistic approach in the management of the aging population is to develop a comprehensive diagnostic paradigm. Since the aging process affects every compartment of the human system and no single compartment functions independently from any other, it is unlikely that a concentration on a particular functional area would lead to the identification of the primary cause or determinant of any dysfunction.
In our attempt to develop a holistic and public health approach to the management of aging in Asia, we have sought to establish a broad-based diagnostic paradigm covering several major areas in health and lifestyle that might be specific to our local Asian population. Within each area of concern, we hope to identify key determinants and, thereafter, help to establish preventive management modalities to assist our population to age gracefully. This article is a brief summary of the preliminary findings using this diagnostic paradigm.
METHODS
Healthy men aged between 30 and 70 years old were included in this study. This report presents the initial results from 319 men with a normal physical examination, who had no history of any major illnesses and had normal liver and kidney functions.
Questionnaire
During the study phase, each subject was asked to answer a questionnaire comprising questions in the various categories:
(1) Biodata;
(2) Education;
(3) Medical and surgical history;
(4) Dietary habits (not a diet analysis but a survey of the normal types of food intake);
(5) Social history: smoking, drinking, exercise, relationship with family, colleagues and friends, stress history, sleep history;
(6) Occupation;
(7) Sexual history;
(8) Physical examination including anthropometric measures.
Tests on blood samples
A 12-h fasting blood sample was collected from each subject and an aliquot was analyzed for kidney and liver functions, full blood count (FBC) and lipid and lipoprotein profiles, including triglyceride levels. Serum from another aliquot was stored at – 80C before being analyzed for various parameters including insulin-like growth factor (IGF)-1, IGFBP3, insulin, prostate-specific antigen (PSA), dehydoepiandrosterone sulfate (DHEAS), total testosterone, sex hormone binding globulin (SHBG), thyroid stimulating hormone (TSH), free triiodothyronine (T3) and thyroxine (T4), and bone markers, such as osteocalcin, cross-linked N-telopeptides (nTX) and others.
Aging and well-being survey
Each respondent completed the Aging Male Symptoms (AMS) survey, comprising 17 questions; this enabled us to compare the symptoms of aging, independently from those symptoms that are disease-related, among the groups of different ages6.
The well-being survey contains 31 items covering a wide variety of symptoms, such as vegetative symptoms, concentration deficits, fatigue, tiredness, dizziness, and symptoms of peripheral neuropathy. The well-being survey was adapted from the Swedish Performance Evaluation System (SPES) computer-aided program . The subject was asked to rate the frequency of occurrence of each symptom during the last 24 h on a four-point scale. The individual’s sense of well-being is dependent on many factors including sleep, stress of duties and hoineostatic disruptions. A higher score indicates a higher number and severity of symptoms, and, hence, a feeling of being unwell.
Bone and whole body scan
Each subject had bone scans at the spine (L2-L4) and the hip and a whole body scan, to provide data on the whole body as well as the regional distribution of bone, lean and fat, including the trunk, abdomen, legs, arms and head. Total body fat, lean mass and bone mass were computed automatically by the DEXA scanner (DPX-L, Lunar Radiation, Madison, WI, USA; software version 1.3z) and the regional distribution of these three indices was defined for the head, trunk, abdomen, legs and arms. The percentage of regional distribution was calculated by taking the fraction in a particular region and dividing it by the total amount and multiplying it by 100.
Anthropometric measurements
The body weight of all subjects was measured (without shoes), using an electronic measuring scale, and their height was measured to the nearest centimeter. The body mass index (BMI) was calculated as weight (kg) divided by the height squared (m^sup 2^). Waist circumference was measured mid-way between the lower costal margin and iliac crest during the end-expiratory phase8. Hip circumference was measured at the level of the greater trochanter8. The waist-to- hip ratio was defined as the waist circumference divided by the hip circumference.
Serum lipid and triglyceride levels
Serum levels of total cholesterol and triglycerides were measured using an automated procedure. The high density lipoprotein (HDL) cholesterol level was determined after precipitation of apolipoprotein B-containing lipoproteins with sodium phosphotungstate and MgCl^sub 2^9. The level of low density lipoprotein (LDL) cholesterol was computed by the following formula: LHL = TC – (HDL+[TG 0.45]). The ratio of total cholesterol to HDL cholesterol was used as the atherogenic index .
Serum measurements of IGF-1, IGFBP3, total PSA, total testosterone and SHBG levels
Serum concentrations of IGF-1, 1GFBP3 and PSA were measured using a radioiminunometric assay with kits purchased from DSL (Texas, USA) with a built-in in-house internal quality assurance program. The interassay coefficients of variation for all three assays were less than 8% for the appropriate concentration ranges.
Total testosterone level was measured using an in-house established scintillation proximity assay validated to the World Health Organization Matched Reagent method. The interassay coefficient of variation for the effective dose range was less than 10%. Serum SHBG levels was measured using the DPC, kit (USA) and the interassay coefficient was less than 10%.
Aerobic and impact exercise scores
Different exercises were given an aerobic and impact score from 0 to 3. Only exercise of at least 20 min was given a score. For example, jogging for at least 20 min has a score of 3 for aerobic and 3 for impact. Brisk walking is given an aerobic score of 2 and an impact score of 2. Swimming is given an aerobic score of 3 and impact score of 0. The Chinese martial art, Tai Chi Chuan, is given an aerobic score of 1 and impact score of 1. Exercise scores were computed over a week. Each day, the maximum score for either aerobic or impact exercises is 3; therefore, if an individual exercises dally for 7 days, the maximum score for a week is 21.
Function tests
Several function tests were included in this study to assess the cognition and general state of health of the individuals. These included:
(1) Handgrip strength, using a dynamometer (Grip-D, Takei Physical Fitness Test, Japan), is a test of small muscle strength. The scores were given in kilograms.
(2) The lung capacity test was conducted using VITAL Vital Capacity Meter (Takei Physical Fitness Test, Japan). Subjects were required to blow into an instrument to measure their lung capacity. The measurement was adjusted for gender and age of subjects, with the mean for gender and age set at 100%. The score was then set as a percentage of the mean of the individual age and gender groups, a feature that is built into the device. The test is a measure of tiredness; a lower percentage score indicates a more tired state.
(3) Measurement of behavioral performance is an important task for monitoring the general health of individuals. There is growing evidence that changes in performance level are some of the earliest indicators of the occurrence of health effects11,12. For this study, we chose two from a battery of 23 tests in the Swedish Performance Evaluation System (SPES)7.
Symbol Digit Match test
The Symbol Digit Match is a test of p\erceptual capacity and speed. In one row, a key to this coding task is given by the pairing of symbols with randomly arranged digits, 1 to 9. The task is to key in, as fast as possible, the digits corresponding to the symbols presented in random order in a second row. Each set consists of nine pairs of randomly arranged symbols and digits, and a total often sets are presented. Performance is evaluated as the mean reaction time and the number of errors for the last 54 pairs of the test. It tests the individual’s ability to interpret and correctly match what he sees as well as the speed of his mental perception. It also involves hand-eye coordination. There are two components to this test, the reaction time (the shorter the better) and the error rate.
Digit Span memory test
The Digit Span memory test is a traditional test of short-term memory capacity. Series of digits are presented on the screen. The digits are presented one at a time, with a 1-s presentation time, and the task is to reproduce the series on the keyboard. Depending on the correctness of the answer, the length of the following series is either increased or decreased. The test starts with a series of three digits and is terminated after six changes from a correct to an incorrect answer. Performance is evaluated as the maximum span length successfully reported and the number of direction changes – the higher the number of changes, the lower the short-term memory.
All the tests and survey performed sought to evaluate the determinants of the aging process and were classified into five major health areas as follows.
Cardio-health
Tests for cardio-health included blood pressure, pulse rate, BMI, lipid and lipoprotein profiles, triglyceride levels, total body fat (based on DEXA whole body scan which has used the Siri formula for computation of total body fat), regional distribution of fat (trunk, abdomen, legs, arms), diet profile, exercise profile, drinking, smoking, medical history and drug intake.
Bone health
Bone health was measured by DEXA scans of the spine (L2-L4, hip, and whole body), bone markers (osteocalcin and serum nTX), exercise profile (impact exercise score), calcium supplementation, vitamin D intake, and other medication for bone health.
Sexual health
Sexual health was assessed by information on any problems with sexual functions, coital frequency, satisfaction with sexual life, status of relationship, any impediment to a better sex life, and therapies for sexual dysfunction.
General health, including stress and sleep history
A person’s general state of health was measured by a general physical examination, liver and kidney function tests, FBC, well- being survey, short-term memory test, perceptual capacity, lung capacity, handgrip strength, aging scores, nutritional profile, lifestyle habits, such as drinking, smoking, hobbies, etc., stress levels at home, stress levels at workplace, serum cortisol level, insomnia, hours of sleep, time of bedtime, history of sleep episodes, such as falling asleep easily, wake bouts, etc., tiredness and alertness the next day.
Major endocrine status
The status of the endocrine system was assessed by somatotropic profiles, of IGF-1, IGFBP3, and insulin, gonadal profiles, including bioavailable testosterone, estradiol, FSH, LH, prolactin, DHT, and SHBG, PSA for men, thyroid function, including TSH, free T3 and T4, adrenal function, including androstenedione and DHEAS.
RESULTS
We have analyzed a sample of 319 healthy men aged between 30 and 70 years old who were involved in our longitudinal study that seeks to establish the major determinants for the identified five major areas. Men were subdivided into different age groups. This report outlines briefly the initial results and inferences peculiar to our population.
Cardio-health
As a criterion for participation in the study, all volunteers were normotensive. It was shown that there were no significant age- dependent changes in total cholesterol, LDL cholesterol, HDL cholesterol, total cholcstcrol/HDL cholesterol ratio, and triglyceride. Regardless of age, 76.8% and 68.8% of men had total cholesterol levels and LDL cholesterol levels above the upper limits of 5.2 nmol/l and 3.4 nmol/l, respectively. In contrast, only 3.9% of men had HDL cholesterol below the 1 nmol/l limit. Hence, overall, the atherogenic risk factor was elevated above 4.5 in 46.4% of the men. In addition, 33.6% of the men had triglyceride levels above the upper limit of 1.7 nmol/l.
There have been sonic difficulties or uncertainties concerning the correlation of cholesterol with other anthropometric measures. Significant correlations were noted among various parameters of the lipid profiles with BMI, waist/hip ratio and body fats (DEXA scans). However, the best correlations were the atherogenic risk factor with BMI, waist/hip ratio and total body fat (Table 1). Total body fat was better correlated with the anthropometric parameters than with the total cholesterol/HDL cholesterol ratio (Table 2).
Aerobic exercises were beneficial m reducing the risk factors in our local population. Adequate exercise was associated with significantly lower levels of triglyceride, total cholesterol/HDL cholesterol ratio, and total body fat, smaller waist and hip circumferences and higher levels of HDL cholesterol (Table 2).
Bone health
Hone health in men is of great interest in a culture whose average diet is low on calcium, about 300-400 mg/day. Overall, the bone mineral density (BMD) of both spine (L2-L4) and the hip revealed no age-dependent changes in Asian men (Higure 1). However, osteoporosis does occur in men, and can occur in men as young as 36 years old. Overall, 1.4% and 1.8% of the men had osteoporosis of the spine and hip, respectively, in contrast to 2.2% and 12.7% of our women, respectively. Of more concern is the observation that 20.7% and 43.6%) of the men had osteopenia of the spine and hip, respectively. These values were not significantly different from those of women, which were 28.7% and 48.8%, respectively.
Sex health
Singapore has been credited as having the lowest coital frequency, less than 100 times per year, among the many countries surveyed13. However, a detailed study of the average man aged between 30 and 70 years old revealed a more disconcerting profile of sex life in Singapore than just the coital frequency. Among the men studied, 16.3% were sexually inactive at the time of the interview. Interestingly, the main reason for their sexual inactivity was a loss of sex interest (42.8%), with relationship problems and being stressed out in life providing the next two most common reasons. In addition, the loss of interest has been noted to be related to the heavy stress at work and work schedule.
Table 1 Correlation coefficients of hpids and triglyceride with anthropometric parameters and total body fat
Coital frequency for men between the ages of 30 and 55 averaged about five to six times monthly and was significantly reduced to about three times monthly in those above 55 years old. Among those who were sexually active, 25.7% had expressed the desire to have more frequent sex, but were unable to fulfill their desire; the primary reason given was that they were too stressed out in life.
General health
Men in this study had stated that they were stressed by work and family responsibilities, with more than 65% perceiving that they were stressed to a level that they might need therapy.
Sleep problem was another issue. Here we are not referring to sleep disorders but rather about the problem of chronic insufficiency of sleep, leading to accumulation of sleep debt, poor quality of sleep, often due to sleep which was not recuperative and hence leading to poor general health. More than 75% of men had indicated that they had difficulty in falling asleep.
The average exercise score of men was less than 40% of the maximum possible in a week, for both aerobic and impact exercises. Men in the 66-70-year age group have significantly higher levels of both aerobic and impact exercises than younger men (Figure 2).
Table 2 Correlation coefficients of body fat and aerobic exercise with lipids, triglyceride and other anthropometric parameters
Figure 1 Bone mineral density in spine and hip in men
Endocrine status
Serum concentrations of IGF-1 and IGFBP3 declined gradually with age, reaching significant levels in the 61-70-year-old age group (Figures 3 and 4). The decline of IGF-1 levels from 210 ng/ml in the 30-35-year age group to 145 ng/ml in the 61-70-year age group represented a decline of about 31%. The decline in levels of IGFBP3 was smaller, about 12%. Both levels of IGF-1 and IGFBP3 were significantly and negatively correlated with age, with the coefficients of correlation being -2.722 and – 0.131, respectively.
Serum total testosterone levels in our local population did not show an age-dependent decline and mean levels remained fairly constant (Figure 5). Serum levels of bioavailable testosterone, calculated using the formula from the ISSAM website, on the other hand, showed a significant decline with age; levels in the two older age groups, 55-60 and 61-70 years, were significantly lower than those in the age group between 41 and 45 years old (Figure 6). Bioavailable testosterone concentration was significantly and negatively correlated with age, with r = -0.105 and p = 0.042.
Serum PSA levels were significantly and positively correlated with age, r = 0.23 and p = 0.000. Mean levels in the two older age groups, 55-60 and 61-70 years, wore significantly higher than corresponding levels in younger age groups of 30-40 and 41-45 years (Figure 7). Interestingly, increases in levels of PSA occurred in the presence of decreased levels of bioavailable testosterone (Figure 6).
Figure 2 Impact and aerobic exercise scores in men. *, impact and aerobic scores of 60-70 age group were significantly higher (p<0.05) than corresponding levels in all younger age groups
Fi\gure 3 Mean IGF-1 levels (ng/ml) in men according to age groups. *, significantly lower (p < 0.000) than corresponding levels in all younger age groups
DISCUSSION
We believed that the suggested diagnostic paradigm would provide a more holistic evaluation of individual health status and would enable us to identify, for individuals, areas of concern that he or she needs to address. In addition, following identification of the key determinants of his/her health status, a more evidence-based approach to the management and the introduction of appropriate tested modalities could be suggested.
Profiling of some of the determinants of aging in samples of the local population, using this diagnostic paradigm, has revealed interesting findings that are relevant to our local Asian population. Coronary heart disease is the second leading cause of death in Singapore today. In the year 2000, it accounted for 24.5% of all deaths14. To a large extent, the morbidity and mortality arising from coronary heart disease could be moderated by adopting preventive measures15. In the light of our findings, it would be expedient to be more proactive in promoting healthy eating in order to reduce the levels of cholesterol and triglyceride, as well as to promote regular exercise so as to reduce the risk of coronary heart diseases among the aging men in our population.
Figure 4 Mean IGFBP3 levels (ng/ml) in men according to age groups. *, levels significantly lower (p = 0.021) than in the 30-40 age group
Figure 5 Total testosterone levels (ng/ml) in men. Total testosterone levels were not significantly different among the various age groups
Bone mass, as measured by the spine BMD or hip BMD, did not change with age. It must be noted, however, that the men in this study were recruited from the general population and were healthy, with no known or history of major illnesses. This might be one possible reason for the constant levels of bone mass in our local men from 30 to 70 years of age. However, our results reveal that osteoporosis is not limited to women alone. We have noted that, regardless of age, osteoporosis does occur in our local men. This observation concurs with earlier reports of a growing bone problem in the elderly16-20. Therefore, we suggested that proactive preventive measures must be adopted, and implemented early so as to reduce the risk of the more debilitating osteoporotic fractures in men as they grow older. In this respect, at the moment, a calcium augmentation trial has been carried out to test the hypothesis that, in our population, which is chronically calcium-deficient, daily calcium augmentation could help to increase bone mass. Preliminary results have shown that, after a year of augmentation, the average increase in bone mass was 4% (unpublished data).
Diet alone is not the only determinant of cardio- and bone health in Asian men; exercise, especially aerobic exercise, has been found to correlate significantly with lower triglyceride levels, total cholesterol/HDL cholesterol ratio, waist and hip circumferences, body fat and higher levels of HDL cholesterol. The level of exercise in men, at the moment, is insufficient. This could be due to the highly urbanized and competitive society in which we are living and men have difficulty in finding the time for regular exercises. Exercise can play an important role in reducing the risk of coronary heart disease. This area certainly warrants further detailed research in the near future to evaluate the scope of the problem and to establish effective modalities to address it.
Figure 6 Bioavailable testosterone (ng/dl) in men. *, levels in this age group were significantly higher than in the age groups 56- 60 and 62-70 years
Figure 7 PSA levels (ng/ml) in men. *, levels in these age groups were significantly lower than all age groups between 51 and 70 years old
The survey of sex health in Singapore revealed that sex life is determined not only by physiological, but also cultural, social and lifestyle factors. In Singapore, lifestyle factors accounted largely for sexual inactivity, and the inability to fulfill desire for more frequent sex. The term ‘lifestyle impotency’ was coined to describe the group of people who were too stressed out in life to have sex21.
The results also showed that age is not a barrier to a healthy sex life. As mentioned, social and economic factors are strong determinants for sex life in Singaporean men. While it is clear that there is a definite role of medical treatment for sexual dysfunctions in a proportion of men who are appropriately diagnosed, counseling to resolve relationship problems and some form of stress therapy must necessarily play a part in the total management of sex life in our local men.
We noted that stress, lack of exercise and problems with sleep are three important determinants for general health. Behavioral factors are important determinants of the aging process22,23. It was interesting to note that men above 65 years old, mostly retirees, exercise twice as much as those in the younger age groups. Hence, greater effort much be expounded to promote healthy exercise routines in the younger working group. For sleep problems, further studies are urgently needed to assess both the impact of surfing the internet until the early hours of the morning and the effect of disrupted sleep on general health, and creative strategies must be formulated to address this crucial area of health.
Hormonal changes with age are well documented24-27. In our local population, similar changes in several hormones, including those of bioavailable testosterone, IGF-1 and IGFBP3, were noted. The mean concentrations of IGF-1 in our local men aged between 30 and 40 years and between 61 and 70 years were, respectively, 210 ng/ml and 145 ng/ml, and were not much lower than corresponding levels of 230 ng/ml and 163 ng/ml reported for a European population28. However, the clinical significance of lower levels of IGF-1 in older men has yet to be evaluated. Our ongoing trial of GH augmentation therapy in a sample of local individuals has shown promising results. It is likely that GH augmentation is beneficial to a highly selected group of aging men who not only show biochemical sign of decline in GH but, with its decline, clear signs of somatic degradation of functions. However, GH should not be used as a panacea of all ills in all aging men.
Although we have shown declining levels of bioavailable testosterone, the basis for instituting androgen augmentation therapy in men whose bioavailable testosterone levels have fallen below a fixed level has not been established and future trials should be carried out.
In the same manner, the usefulness of screening for PSA in problems with the prostate will have to await data from the longitudinal study.
CONCLUSION
We have set in place a diagnostic paradigm which appears to be useful for the management of the problem of aging in our local population. This paradigm could be used for management of individuals as well as for population research. When combined with the establishment of evidence-based management modalities, it will provide a useful tool for the formulation of a holistic approach to the aging problem in Asia and to derive modalities to help to prevent the preventable and delay the inevitable. For developing countries in Asia to be more effective in tackling the health needs of the aging population, these management modalities must be at minimal cost and with maximum public accessibility.
ACKNOWLEDGEMENTS
We would like to thank the staff of the Endocrine Laboratory, Mr Baharudin bin Said, Ms Eng Sok Kheng, Poon Peng Cheng, Ng Hwee Lee and Zhao Hui Qin for their assistance in the study. We want to acknowledge the clinicians from the Department of Obstetrics and Gynecology for their assistance in the clinical screening of the subjects. This study is supported by funding from the National University of Singapore under the Academic Research Fund scheme.
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V. H. H. Goh, C. F. Tain, T. Y. Y. Tong, H. P. P. Mok and S. C. Ng
Department of Obstetrics and Gynaecology, Faculty of Medicine, National University of Singapore, Singapore
Correspondence: Professor V. H. H. Goh, Department of Obstetrics and Gynaecology, Faculty of Medicine, National University of Singapore, Singapore
Copyright CRC Press Jun 2004