Underweight
The risk of being underweight (instead of normal weight) increases with age in the Philippines and Taiwan. In one Taiwanese Sleep Study (Tang 2007), 3.22% of the studied cohort was underweight. Another Taiwanese cohort of 778 cases was recruited in the multinational Global Lower Extremity Amputation (LEA) Study. Risk factors included age, sex, smoking, BMI, hypertension, systolic (SBP), diastolic blood pressure (DBP), and LEA level. Mortality was ascertained from the National Death Registry. With a follow-up period of up to 6.5 (median: 4.0) years and 1239.17 patient-years, 214 patients died. The underlying cause of death was recorded as diabetes mellitus; 57.9% died. After adjustment for age and sex twp variables, then smoking, SBP and underweight are predictive for mortality. (Tseng, 2007)
Underweight and Overweight
A sleep-laboratory-based Taiwanese study, using Asian BMI criteria, for those subjects who were underweight: with the BMI of 18.5 included 0.85% of the population. For those with the BMI< 18.5, it was three times greater, 2.56 % (Tang, 2007). Tang stressed the importance of Asian BMI, the upper limit of normal BMI in Far-East Asian is 23.5 kg/m2. (Table 6)
Table 6. The data of a national survey in Taiwan that was conducted in 1999 *
|
Variables |
Male (n = 1,243) |
Female (n = 1,189) |
|
Age (years) |
72.7 (72.1-73.2) |
73.0 (72.5-73.4) |
|
Height (cm) |
162.9 (162.6-163.3) |
149.9 (149.3-150.5)* |
|
Weight (kg) |
61.4 (60.7-62.1) |
53.9 (53.0-54.8)* |
|
BMI (kg/m2) |
23.2 (23.0-23.5) |
24.0 (23.7-24.4)* |
* Elderly Nutrition and Health Survey in Taiwan (1999-2000): research design, methodology and content’ was not published until 2005.
Among other studies that adapt Asian BMI criteria, in Taiwan, there is a study for checkup population in 2001 used mean BMI in Asian criteria compared with socioeconomic status (SE) for the elderly aged 65 years and over. (Chien, K.L., 2004)
Due to changes in socioeconomic status and dieting habit, there are other publications that employ Asian BMI criteria. There were reports on dietary changes from 1978 to 2003 in the Philippines. The relationship between BMI and Sleep Apnea has been identified. Trends of dietary changes from 1978 to 2003 in the Philippines might affect the composition of BMI, and thus secondarily influence sleep apnea. The expanding Filipino economy from 1998 to the 2003 reduced the consumption of starchy roots and tubers from 37 g/day in 1978 to 19 g/day in 2003. (Jenkins at el, 2007). Conventional and cultural food consumption is primarily from yams and tubers is diminishing. A double burden of malnutrition and high food costs was illustrated in case studies carried out in six developing countries (FAO Corporate Document Repository of the Philippines). Such a trend might affect the composition of BMI, and thus consequently affect sleep apnea.
In Taiwan, there is the higher proportion of underweight people among the elderly (70+) than among the near elderly (53-69 y). In Taiwan, an analysis reveals that with a sample size for the elderly cohort (70+ years) and near elderly cohort (53-69 years) 1855 subjects, and near elderly cohort (53-69 years) 2014 subjects , the number of was 211 for the elderly and 65 for the near elderly respectively. When expressed as a percentage, the values are 1.13% for the former, and 0.32% for the latter (SA and Larsen, 2007). Based on clinical studies, body weight peaks in the 50s and remains stable or decreases after the mid- or late 60s. The weight data for Taiwanese elderly data seem to fit this pattern.
Underweight is more prevalent in the Philippines (29.9%) than in Taiwan (6.4%). By comparison, overweight is more prevalent in Taiwan (29.3%) than in the Philippines (12.2%) (Jenkins et al 2007) This difference can be attributed to the level of economic development and their impact on nutrition transition of the two societies. Different sets of factors are related with the two extremes of body weight. The risk of being underweight instead of normal weight increases with age in both countries. Old adults aged from 70 to 80 years have had less exposure to the nutrition transition towards the Western diet than those aged from 50 to 70 years. A cohort effect might explain why 50 to 69 year Taiwanese adults have a greater risk than the older old Taiwanese adults, aged from 70 to 80 years of being overweight instead of normal weight. The absence of this pattern in the Philippines may be due to its lower economic development relative to what in Taiwan.
Men are generally less likely than women to be either underweight or overweight. In the Philippines, almost 30% of older adults are underweight. (Table 1)
A study of under-nutrition in Taiwan follows. A simple questionnaire adopted from the Mini Nutritional Assessment (Sa & Larsen, 2007) was recently employed as a preliminary screening method for Taiwanese elderly individuals who were at increased risk of nutritional inadequacy. The proportion of Taiwanese elderly who were regarded at the high risk of under-nutrition increased with age, ranging from 0.88% for 53 to 60 year-old subjects, 1.86% for those subjects aged 60 to 70 years, 3.6% for those from 70 to 80-year-olds, and 5.3% for those subjects aged older than 80-year-old (Tsai, A). Not surprisingly, different sets of factors are related with the two extremes of body weight. There are both similarities and differences in predictors across settings. The risk of being underweight instead of normal weight increases with age in both settings, because of a cohort effect; the older old adults have had later and lesser exposure to the nutrition transition towards the Western diet than have the younger old adults. A cohort effect might also explain why younger-old (50 to 69 year old) Taiwanese adults have a greater risk than the older old (70 years and over) Taiwanese adults of being overweight instead of normal weight. The absence of such a pattern in the Philippines may be due only to its lower level of economic development relative to Taiwan. (Table 1)
Several studies comparing OSA in Caucasians and Asians have shown that Asian subjects have a greater severity of illness, as indicated by higher AHI, contrasted with Caucasian patients matched with age, gender, and BMI. Asians generally have a higher percentage body fat than Caucasians of the same matched items. Hence, making cross-ethnic comparison of body habitues using absolute BMI values may be misleading as previously mentioned. Culture and eating habit have to be taken into account. For example, the people in Gujarat state of India are mostly merchants, instead of farmers; they are fond of food made from sweets. Generally, the prevalence of being overweight will become much greater in urban areas and among the rich.
The relationship between obesity and socio-economic status (SES) has been altered as countries develop. Likewise, that between obesity and urbanicity will change as countries grow. Urbanites are inclined to have higher BMI than their rural counterparts. Other studies have found differences by age and gender. Therefore, BMI has been affected accordingly, which in turn influences sleep apnea. The drawback of one of the Taiwanese studies (Liu & Liu, 2004) is the lack of BMI data. Both Taiwanese and the Filipino other studies cover weight, height and BMI data. Nevertheless, there are still some issues that bear further studies. There are clues to determine and to find the subgroups that are most vulnerable to abnormal weight, which is affecting BMI, but not height. Adequate attention should be paid to the localities where economic development that benefits only the urban elite, such as in Brazil (Jenkins et al, 2007).
Visceral fat accumulation of obese and overweight patients should be considered. The secondary increase of the negative intrathoracic pressure by respiratory efforts may play a role in the pathophysiology of SDB. The standard PSG used in most of sleep studies does not include the measurement of esophageal pressure (Pes), which represents the intrathoracic pressure. Hence, the upper airway resistance syndrome is often overlooked because the severity of OSA has already been evaluated by the AHI.
Obesity, BMI and socioeconomic status (SES) are important issues. Huang et al (2005) report on obesity in the elderly and its relationship with cardiovascular risk factors in Taiwan. Conversely, there is a study that assesses the association between socioeconomic status (SES) and overweight and obesity among near elderly (aged 53-69) and elderly (age 70+) people, using a longitudinal survey data in Taiwan. In mainland China, status and current income were positively related with BMI among near elderly and elderly men. SES was not associated with BMI in elderly women, while education was inversely related with BMI among near elderly women. The shifting of paradigm in the relationship between SES and overweight/obesity between near elderly and elderly women suggests a budding social inequality in overweight and obesity in Taiwan. The signs indicate that prototypes of social gradients in obesity are acclimatizing to socioeconomic and cultural background (Sa and Larsen , 2007).
There is some complementary provision that the desirable body image may also become more westernized. A propensity in the cultural insight of body weight is currently affected on the younger generation by fashion-models. This prevails in societies that where the younger generation wants to be more fashionable, while among the older generation wants to be ‘slimmer’. The above tendency is found in the Philippine, Taiwan, in other Asian countries like India. The traditional culture of Taiwanese and the Philippines tend to recognize a more appealing physical body structure. Such structure contrasts to the existing Western physical standard to be socially acceptable, presentable and desirable.
Working through examples can help highlight the issues involved and demonstrate how to conduct a possible solution. More extensive comparisons may assist in recognizing the subset groups that are most susceptible to abnormal body weight, and consequently, lead to hypertension and then to sleep apnea. It would be practical and educational to account for the role of public health and sleep hygiene together with National Cholesterol Education Program (NCEP). Conceivably, nutrition programs that keep a tight rein on hypertension and excessive weight will prevent sleep apnea for all the steps of the social-class ladder and the rich and poor in both societies.
Obviously, both developed and underdeveloped countries conceivably need more sleep studies (See Tables 1-5). Patterns of being underweight and overweight, which affect sleep apnea, should be studied in more details in both societies.
Cigarette Smoking
In the Philippines, the population is predominantly young. Cigarette smoking is a problem. In the Philippines, cigarettes can be bought one at a time, which makes them easily accessible to adolescents and children. Increasing fat intake, diabetes, high cholesterol levels, and CHD are now increasing health problems in the adult population. The population is spread over many islands, and there are diverse ethnic groups. Thus collecting epidemiological data is difficult. One of the unusual strengths in gathering data is that the Philippines are well supplied with dietitians. Filipino experts are committed to continuing health education.
In Taiwan, the elderly people are increasing in number. Unfortunately, the problem of sleep disturbance in the elderly has not been sufficiently studied. However, there is a repot on 6,406 adult subjects (41.4% women) from January to December 2001 from the health-screening program in a tertiary hospital. C reactive protein (CRP) was found positively related to smoking status (Chien K. L. et al, 2003) High CRP levels were strongly associated with metabolic syndrome. CRP significantly associated with smoking and metabolic syndrome. Inflammation, smoking and atherosclerotic risks were interrelated among healthy young and elderly Taiwanese. (Chien KL et al, 2003) For elderly adults, CRP’s relationship with sleep disturbance needs further evaluation in the two societies. It is unclear which metabolic syndrome risk factor components could predict CRP levels and possible interaction with smoking. Elderly smoking at nights may be related to insomnia; this should to be evaluated. Sleep apnea syndrome is an important risk factor for atherosclerosis, cardiovascular morbidity, and cigarette smoking. Smoking interacts with sleep apnea to increase cardiovascular risk (Lavie et al, 2007).
Latent Clinical Factors for the Elderly People
The elderly, a factor that is worthy of discussion in relation to the height distribution is the latent clinical factor. It is the rate people, mostly the elderly, have height loss due to ageing. The elderly people have hormonal changes, which are related to loss of bone density. Latent Clinical Factors are clinically unobservable. In the current work of this author’s observation of the height loss, there is a lack of knowledge about their rate of height loss. On the parlance of the latent variable modeling, there might be a true nature, as whether a fast or slow shrinker of height in the elderly people – and this is what really causes subjects to fall into one or the other statistical distribution that one can possibly observe. The latent variable should explain the observable variability. In addition, the latent variable should have a theoretically sound basis. There are many equivalent models of the correlations among observed variables. Hence, a latent variable (or more than one) requires some serious hypothesizing to link the possible relationship of height to sleep disturbance in the elderly people.
Health Insurance Coverage and its Effect on Sleep Education and Sleep Studies
For Taiwanese, the National Health Insurance plan in Taiwan provided and provides the expense of PSG, with 1/10 of its co-payments to be paid by a patient per test. Therefore, the subjects were not particularly richer than the average, for any full payment of the expensive PSG. Prior to March 1995, 12.7 million people, about 60 percent of the Taiwanese population were eligible to benefit from thirteen public health insurance plans. More than 8.5 million were uninsured. Many were children and half were over sixty-five. After six years of planning, the Taiwan government launched the National Health Insurance (NHI) program on March 1, 1995. In 2008, 99% of the Taiwanese population are insured. By comparison, National health insurance is not available in the Philippines.
There are other issues: urban-learned Western eating habits, patterns of life style, nightlife and entertaining activities into rural parts, versus those in rural areas that either directly or indirectly affect sleep patterns.
The Poor Elderly Get Less Sleep
The elderly people living in poverty get less sleep than those in higher SES group. This is an important societal problem, regardless of the various cultural backgrounds. Examples of the influence of poverty on the elderly people can be found, even in advanced countries like U S A. There is recent evidence that the obesity burden tends to shift towards the poor as countries develop (Monteiro, 2004). Obesity has an adverse effect on sleep apnea, and is more prevalent in males than females. Furthermore, many health disparities even are linked to inequalities in education and income (Drewnowski, 2004). Over 47 million Americans uninsured and even more underinsured.
Approximately, 18 million Americans suffer from obstructive sleep apnea (OSA). Unfortunately 10-20% of these people are aware of that they have OSA and are being treated. An increasing number of an aging population and obeseity will lead to an increase in OSA. Elderly people who are living in poverty get less sleep than those in higher SES group; this will exacerbate a bad situation ( McCamy Taylor, 2007). In the Mindanao region of the Philippines, women cried out ‘we boil bananas for our children when food is not available.’ In some cases, when the Department of Agriculture distributes corn seeds, we cook these seeds instead of planting them. Ironically, they borrow money to acquire these seeds. The cycle of poverty continues, as they are unable to pay for these loans.
Moreover, some indigenous people feel that they are ‘gradually losing control over their ancestral lands. In some areas, non-indigenous people get titles to indigenous people’s lands in connivance with unscrupulous government representatives.’ In the Philippines, approximately 16 to 27% of the population would remain poor in 2010. As a result, the Philippine will have to move rapidly if poverty is to be reduced perceptibly.
Poverty and Obesity
There are interrelations between socioeconomic factors and obesity when taste, heavy dietary energy, and food prices are employed as superseding factors. Increasingly Americans are becoming overweight and obese while consuming more added sugars and fats and spend a lower portion of their throwaway earnings on food (Drewnowski, 2004). A similar trend occurs in the Philippines and Taiwan.
Biofuel production drives up the food price, and damages the environment and speeds up global warming. Food should not be so expensive that many elderly, disabled and homeless people will be unable to feed themselves and their children. The increase food prices can raise people’s anxiety and adversely affects their sleep quality (Braun and Pachauri, 2006).
National Health Insurance
As previously mentioned, by 2005, nearly 99 percent of the Taiwanese population was covered by National Health Insurance (NHI). Despite public satisfaction rates of over 70 percent, an increasing number of elderly people has given rise to changing patterns of health problems. As the proportion of elderly people increased, chronic cardiovascular diseases have replaced infectious diseases as the major health problem among adults. In Taiwan, the Ministry of the Interior is planning to alter its immigration policy by adding a program aimed at attracting foreign white-collar professionals. According to ministry statistics, the Taiwanese birth rate in 2002 was 11.02 percent, compared to 49.97 percent in 1951. The number of children in the average family was 1.34 in 2001, down from 7.04 in 1951. The Ministry of Interior of Taiwan deals with an increasing number of elderly people, developing ways to raise the birth rate and altering the immigration policy. With such an increasing number of elderly people, the problem of sleep disturbance has not been addressed. Like many developing countries, the Philippines are experiencing both rapid urbanization and an ageing population. In the Philippines, with such an increasing number of elderly people, the problem of their sleep disturbance has not been suitably attended.
Limitations of Cross-Cultural Sleep Studies
There is no definite information of the prevalence and severity of obstructive Sleep Apnea in Asian snorers, including Taiwan and the Philippines. Conversely, the relationship between the AHI scores and the immediate consequences in the asymptomatic and/or undiagnosed general elderly population needs more study (Tang 2005, Tang 2006a, Tang 2006b). It is important to have both subjects and controls in the same age group in a sleep study. Due to the lack of WHO reports on Taiwan, together with the delay of publishing a national survey in Taiwan, some sleep studies had no choice but to analyze two different samples (participants) from two different time periods. For example, in a study, the subjects were from 2002 to 2003, while controls were from 1993 to 1996 (Tang, 2007). The limitations of studies such above include the selection of study subjects might be challenged. Such as the above is also potentially subject to sources of bias and variation, and the generalization of the results may be limited. Therefore, the findings in such studies might underestimate the prevalence of sleep-disordered breathing (SDB) in the entire population in a certain country. Hence the relationship between the AHI scores and the immediate consequences in the asymptomatic and/or undiagnosed general elderly population needs more study.
The comparison data from a national survey (1993-1996, Taiwan) was used in one of the studies of Taiwanese. Participants in that survey were not taking the nocturnal PSG. The survey reported on the population a few years earlier than the beginning of the sleep study in Taiwan (Tang, 2007), but survey was not published until 1999 for public reference in Taiwan, which was merely two years before the beginning of the sleep study (Tang, 2007). The height and weight measurements should have been obtained from the census data to have validity in any comparison. Unfortunately, comparative year to year comparative data do not exist. The report of ‘Elderly Nutrition and Health Survey in Taiwan (1999 to 2000): research design, methodology and content’ was not published until 2005, three years and eleven months after the conclusion of a Taiwanese sleep study (Tang, 2007).
Most of the sleep studies discussed in this article are cross-sectioned. Most of such variables studied are restricted by the application of a dichotomous measure of urbanicity. Modifications do happen in sleep disturbance and apnea, along with metabolism and dieting habit during the life span; such modifications may decrease the odds of being overweight for those who survive to the age of 70 years and over. Given the cross-sectional nature of most of the studies referred here, elderly participants who live long enough to join the studies naturally were the survivors. On the tapis of such a cross-sectional nature of studies cited in this article, it is difficult to justify that changing metabolism, dieting and nutrition habits across the life span may mitigate the effects of being obese or overweight for those who survive to the older age. Hence, there is a need for the proper longitudinal survey for the future work in this area.
Associations between obesity and urbanicity will alter as countries develop, as has the relationship between socio-economic status (SES) and obesity. Current studies are restricted not only to cross-sectional studies as outlined in the aforementioned section, but also in the use of a dichotomous gauge of urbanicity. The measurement of the latter needs improvement. The application of a dichotomous description of urbanicity, while convenient and frequently helpful, can as well be challenging (Champion 2004, McDade 2001, Vlahov 2002, and Yach 1990).
Conclusion
The study of sleep disturbance in the elderly is a new area of scientific research. This is a research field that has largely been neglected for this age group. Probable reasons for this are numerous. One of the most likely factors may be due to a combination of the lack of documented data, together with the complexity of human sleep itself. This field is an undiscovered entity, especially in sleep research on the age groups mentioned in this article. All patients are vulnerable, especially those who are elderly. Thus, the difficulty is due to the problem faced in obtaining volunteers as well as the philosophical and theological undertones people associate with ”the sleep when they are at the end stage of their life". Moreover, there is as well the misconception of sleep study on ‘those who haven’t many years left anyhow’ in general. Additionally, there is difficulty in recognizing cross-cultural differences among the elderly people’s sleep disturbance. Hence, as aforementioned, the objective of this article was to provide a broader understanding of the complicated relationship of various aspects of sleep apnea in the age group studied. Results from this article may provide direction for fruitful areas of future research.
National differences in epidemiology of sleep apnea may be helpful for better understanding of triggers and pathogenesis of this condition.
Thus this article can be used to help establish proper concepts, to improve the wellbeing of the elderly people with sleep disturbance in countries regardless of developing status of the nation. Further study is necessary to investigate whether the differences between two societies are caused the limitation of hospital-based study or by differences in ethnicity.
Finally, society helps keep a person ‘up to the times’, and enables her/him to refurnish her/his ‘mental shop with the latest wares’, see the 1904 statement by William Osler (18491919) (Osler, 1904).
