Association of decreased frequency of conversation with depression, oral function and eating alone: A cross-sectional study of older adults during the COVID-19 pandemic.

AIM: This study examined the associations between geriatric factors and decreased opportunities for conversation among older adults amid a period of self-restraint during the COVID-19 pandemic. METHODS: A cross-sectional questionnaire-based survey was carried out in October 2020. The participants were 204 residents aged ≥65 years staying at a private care home in Kyoto city, Japan. Logistic regression analysis was carried out with the reduction of conversation opportunities as the dependent variable, and geriatric factors as independent variables after adjusting for age and sex. We compared the decreased frequency of opportunities between residents in the assisted living wing and in the nursing care wing of the private care home. RESULTS: The percentages of respondents who reported a decrease in the opportunities for conversation among themselves were 43.9% for residents in the assisted living wing and 19.7% for those in the nursing care wing. After adjusting for age and sex, the opportunities for conversation was significantly associated with the basic activities of daily living (OR 1.07, 95% CI 1.01-1.12), instrumental self-maintenance (OR 1.25, 95% CI 1.08-1.46), intellectual activity (OR 1.35, 95% CI 1.09-1.66), depression (OR 1.13, 95% CI 1.04-1.23), depressive mood (OR 3.83, 95% CI 1.98-7.42), decreased motivation (OR 3.11, 95% CI 1.58-6.12), appetite loss (OR 4.32, 95% CI 1.54-12.07), swallowing function (OR 1.05, 95% CI 1.00-1.10), chewing difficulty (OR 2.50, 95% CI 1.31-4.75) and eating alone (OR 2.5, 95% CI 1.35-4.62). CONCLUSION: Decreased opportunities for conversation was more perceived among older adults with higher daily functioning, suggesting that it is associated with depressed mood, oral function and solitary eating. Geriatr Gerontol Int 2024; 24: 385-391.

Association between glucose tolerance and mortality among Japanese community-dwelling older adults aged over 75 years: 12-year observation of the Tosa Longitudinal Aging Study.

AIM: Although the relationship between impaired glucose tolerance (IGT) and mortality has been investigated in diverse populations, few studies have focused on older populations. This study aimed to investigate the relationship between glucose tolerance and overall mortality among populations aged ≥75 years. METHODS: Data were obtained from the Tosa Longitudinal Aging Study, a community-based cohort survey conducted in Kochi, Japan. According to the results of a 75-g oral glucose tolerance test conducted in 2006, the participants were classified into four categories: normal glucose tolerance (NGT), impaired fasting glucose (IFG)/IGT, newly diagnosed diabetes mellitus (NDM), and known diabetes mellitus (KDM). The primary endpoint was overall mortality. Differences in overall mortality among the four categories were evaluated using the Cox proportional hazards model. RESULTS: During a median of 11.5 years of observation, 125 deaths of the 260 enrolled participants were recorded. The cumulative overall survival rate was 0.52, and the survival rates of NGT, IFG/IGT, NDM, and KDM were 0.48, 0.49, 0.49, and 0.25, respectively (log-rank test, P = 0.139). Adjusted hazard ratios (HRs) for mortality in the IFG/IGT and NDM groups compared with the NGT group were 1.02 (95% confidence interval [CI], 0.66-1.58) and 1.11 (95% CI, 0.56-2.22), while mortality in the KDM group was significantly higher than that in the NGT group (HR, 2.43; 95% CI, 1.35-4.37). CONCLUSION: Mortality did not differ significantly between the IFG/IGT, NDM, and NGT groups, but was higher in the KDM group than in the NGT group. Geriatr Gerontol Int 2023; 23: 341-347.

Periodontal status is associated with oral function in community-dwelling older adults, independent of dentition status.

OBJECTIVE: To determine whether periodontal status is associated with oral function, including masticatory performance and occlusal force, among community-dwelling older adults. BACKGROUND: Although a potential association between periodontal status and oral function has been reported, variations in the root surface area (RSA) of each tooth have not been considered. METHODS: We used data from a population-based study involving community-dwelling older adults. The RSA with periodontal ligament (RSA-PL), which quantifies the RSA attached to the periodontal ligament and alveolar bone, was calculated based on full-mouth periodontal examination. Masticatory performance was assessed using spectrophotometric measurement of the color (a* value) of color-changing chewing gum. The bilateral maximal occlusal force (MOF) was measured using a pressure-sensitive sheet and dedicated software. The associations of the RSA-PL, a quantitative marker of periodontal tissue support, with the a* value and MOF were assessed using linear regression models. RESULTS: The analyses included data from 250 adults [60.8% women; age, mean (standard deviation) 82.5 (5.0) years]. On average, the study participants had an RSA-PL of 26.3 cm2 , a* value of 25.0, and an MOF value of 555.1 N. After adjustments for potential confounders, including dentition status, age, sex, dental visit regularity, smoking status, physical activity level, depressive symptoms, a history of stroke or diabetes mellitus, and body mass index, the RSA-PL was found to be associated with the a* value [coefficient (per 1 cm2 increase): 0.16, 95% confidence interval (CI) 0.10-0.22)] and MOF (coefficient: 9.2, 95% CI 5.3-13.1). CONCLUSION: This study demonstrated that greater amounts of remaining tooth-supporting structures, indicated by higher RSA-PL values, were associated with better masticatory performance and a higher occlusal force among community-dwelling older adults.

Older adults' preferences for and actual situations of artificial hydration and nutrition in end-of-life care: An 11-year follow-up study in a care home.

AIM: To clarify older adults' preferences for and actual situations of artificial hydration and nutrition (AHN) in end-of-life care in a care home. METHODS: Participants were residents of a care home who had completed advance directives regarding preferred methods of AHN from 2009 to 2018. Advance directives alone were available from April 2009 to June 2016 (Wave 1), and advance care planning for AHN including advance directives was introduced in July 2016 (Wave 2). AHN preferences included (i) intensive methods (percutaneous endoscopic gastrostomy, nasogastric tube feeding and total parenteral nutrition), (ii) drip infusion, and (iii) oral intake only. Participants were followed until the end of 2020, and we checked whether decisions about AHN were based on older adults' preferences. RESULTS: In total, 272 participants had completed advance directives. Most participants preferred "oral intake only" (59.5%), followed by drip infusion (32.0%) and intensive methods (8.5%) in advance directives. Ninety of the 272 participants completed advance directives twice; 83.3% did not change their AHN preferences from Wave 1 to Wave 2. By the end of 2020, 93 of the 272 participants died in the care home. AHN was provided according to older adults' preferences in 48.9% (oral intake only), in 51.4% (drip infusion) and in 55.6% (intensive methods) of cases respectively. CONCLUSIONS: Most participants preferred oral intake only, and their preferences were reflected in decisions about actual situations of AHN in end-of-life care. To prepare for advanced dementia and senility, early advance care planning for AHN should be promoted. Geriatr Gerontol Int 2022; 22: 581-587.

Gynecological aspects as a component of comprehensive geriatric assessment: A study of self-rated symptoms of pelvic organ prolapse among community-dwelling elderly women in Japan.

OBJECTIVES: Despite the reported 'male-female health-survival paradox', no components of the comprehensive geriatric assessment (CGA) routinely used in the field of geriatrics focus on female-specific symptoms. To investigate the impact of gynecological factors among elderly women, we noted the gynecological history and examined the association between self-rated symptoms of pelvic organ prolapse (POP) and CGA. STUDY DESIGN: This community-based, cross-sectional study in Japan included 164 community-dwelling women aged ≥75 years. MAIN OUTCOME MEASURES: The main outcome measures were the Pelvic Organ Prolapse Distress Inventory-6 (POPDI-6), activities of daily living (ADL), and Timed Up and Go (TUG) test. Self-rated symptoms of POP were assessed using POPDI-6, and the participants were dichotomized into POPDI-6 >0 (symptom group) and POPDI-6 = 0 (no-symptom group). Several components of the CGA were compared between the groups with and without symptoms of POP and the association with POPDI-6 score was analyzed by multiple logistic regression analysis. RESULTS: Compared with the no-symptom group, the symptom group had significantly longer TUG test time (≥13.5 s) (P = 0.024) and difficulty in basic ADL (score <21) (P = 0.02). In multiple logistic regression analysis, basic ADL <21 and TUG time ≥13.5 s were significantly associated with POPDI-6 >0 (odds ratio [OR] = 2.78; 95% confidence interval [CI] = 1.10-7.06 and OR = 3.45; 95% CI = 1.01-1.24). CONCLUSIONS: Self-rated POP symptoms were associated with CGA components among community-dwelling elderly women. Evaluating POP symptoms as part of the CGA could be meaningful for improving physical and psychological health in elderly women.

Effects of a Low-Salt and High-Potassium Diet on Arterial Stiffness and Left Ventricular Function in Indigenous Papuans.

Background A sodium-restricted diet represents a potential non-pharmacological strategy for improving blood pressure, arterial stiffness, and left ventricular (LV) diastolic function. We investigated age-related differences in LV structure and function and the relationship between LV function and central hemodynamics in an indigenous Papuan population, who maintain a traditional lifestyle, including a low-salt and high-potassium diet. Methods and Results We measured LV dimensions, transmitral blood flow, and mitral annular tissue velocities through echocardiography and Doppler imaging. Blood pressure and brachial-ankle pulse wave velocity were measured using an automatic device (Omron). Central blood pressure and wave reflection parameters were estimated via oscillometry (Mobil-O-Graph, using European calibrations). A total of 82 native Papuans (median age, 42 years; 38 women; no blood pressure treatment) were enrolled. Age-related difference in brachial systolic pressure was modest but significant, and brachial-ankle pulse wave velocity significantly increased with age; however, LV mass index remained unchanged. LV ejection fraction and global longitudinal strain were preserved; mitral A-wave velocity and average E/e´ increased; and e´ and E/A decreased with age. Brachial-ankle pulse wave velocity and spot urine Na/K were positively and independently correlated with E/e´. Age and heart rate were inversely associated with E/A. In conclusion, LV systolic function was preserved; however, LV diastolic function decreased with age in Papuans. Moreover, age-related arterial stiffening, but not wave reflections, was inversely related to LV diastolic function. Conclusions Our results suggest that arterial and LV stiffness may not be altered by sodium restriction. Longitudinal studies are warranted to elucidate the effects of diet on arterial and LV function.

A population-based cross-sectional study of the association between periodontitis and arterial stiffness among the older Japanese population.

OBJECTIVE: To investigate the potential association between periodontitis and arterial stiffness among the older Japanese population. BACKGROUND: The prevalence of periodontitis is increasing in Japanese older adults. Arterial stiffness increases the risks of cardiovascular events and death, morbidity, and dementia. METHODS: This secondary analysis of data from a cross-sectional study evaluated the periodontal inflamed surface area (PISA), reflecting the amount of inflamed periodontal tissue that was estimated by a full-mouth periodontal examination. Severe periodontitis was defined per the parameters provided by the Centers for Disease Control/American Academy of Periodontology. The Cardio-Ankle Vascular Index (CAVI) was used for measuring the overall stiffness of the artery, and higher CAVI indicated increased arterial stiffness. An ordinal logistic regression model was used to evaluate the association between periodontitis and arterial stiffness. RESULTS: The analysis included 185 Japanese adults [35% men; age, mean (standard deviation) 80.2 (4.4) years]. The average PISA and the prevalence of severe periodontitis were 64.4 mm2 and 27.6%, respectively; 54 (29.2%), 56 (30.3%), and 75 (40.5%) participants were stratified to the CAVI < 9, 9 ≤ CAVI <10, and CAVI ≥ 10 groups, respectively. After adjusting for potential confounders, the odds ratio of the prevalence and severity of arterial stiffness evaluated using CAVI was 1.06 [95% confidence interval (CI) 1.01 to 1.10] for PISA per 10 mm2 and 2.12 (95% CI 1.09 to 4.11) for severe periodontitis. CONCLUSION: Periodontitis was associated with arterial stiffness among Japanese older adults. Further studies are needed to investigate whether arterial stiffness is an intermediate factor in the pathway between periodontitis and systemic diseases, including cardiovascular disease and dementia.

Combined effect of poor appetite and low masticatory function on sarcopenia in community-dwelling Japanese adults aged ≥ 75 years: A 3-year cohort study.

OBJECTIVE: This study aimed to investigate the longitudinal association of the combination of poor appetite (PA) and low masticatory function (LMF) with sarcopenia in community-dwelling older adults. METHODS: In total, 173 community-dwelling Japanese adults aged ≥ 75 years participated in the 3-year cohort study. Appetite assessment using the Simplified Nutritional Appetite Questionnaire (SNAQ) and masticatory function assessment using spectrophotometric measurement of differences in gum colour before and after masticating colour-changeable chewing gum (ΔE*ab) were performed at baseline. SNAQ score of ≤ 14 was defined as PA. The lowest tertile of ΔE*ab was defined as LMF. Follow-up examinations were administered annually over a 3-year period to determine sarcopenia incidence, which was defined by the criteria proposed by the Asian Working Group for Sarcopenia. Adjusted hazard ratios (HRs) of sarcopenia incidence according to the presence of PA and LMF were calculated using Cox proportional hazards regression models. RESULTS: At baseline, 81 participants (46.8%) had neither PA nor LMF, 34 (19.7%) had PA alone, 35 (20.2%) had LMF alone, and 23 (13.3%) had both PA and LMF. On follow-up, 31 participants (17.9%) developed sarcopenia. After adjusting for covariates, the adjusted HR for sarcopenia in participants with both PA and LMF was 4.4 (95% confidence interval = 1.6-12.2) compared with those without PA or LMF. PA or LMF alone was not significantly associated with sarcopenia development. CONCLUSIONS: Coexisting PA and LMF increase the risk of sarcopenia development among community-dwelling Japanese adults aged ≥ 75 years.

Periodontitis, periodontal inflammation, and mild cognitive impairment: A 5-year cohort study.

BACKGROUND AND OBJECTIVES: Identification of modifiable factors for mild cognitive impairment (MCI) is important since individuals with MCI are at a high risk of dementia and disability. Previous studies have suggested a potential association between periodontitis and cognitive impairment, but the results remain inconclusive. We designed a 5-year longitudinal study to explore the association between MCI and periodontitis and periodontal inflammation in older adults. METHODS: This study included 179 community-dwelling dentate individuals (62 men and 117 women, average age: 80.1 years). A full-mouth periodontal examination at six sites per tooth was performed at baseline. Case definitions provided by the European Workshop in Periodontology Group C (EWP definition) and the Centers for Disease Control/American Academy of Periodontology (CDC/AAP definition) were used to define severe periodontitis. Additionally, the periodontal inflamed surface area (PISA), reflecting the amount of inflamed periodontal tissue, was calculated using clinical periodontal parameters. Follow-up cognitive examinations for MCI diagnosis were performed by neurologists 1, 2, 3, and 5 years after baseline. Odds ratios (ORs) for MCI according to the presence of periodontitis and periodontal inflammation at baseline were calculated using multilevel mixed-effects logistic regression. RESULTS: At baseline, 56.4% and 27.4% of the participants had severe periodontitis by the EWP and CDC/AAP definitions, respectively. After adjusting for follow-up period and other baseline health characteristics (age, sex, smoking status, educational level, physical activity level, obesity, depression, and diabetes), severe periodontitis by either definition was significantly associated with MCI (for the EWP definition: adjusted OR = 3.58, 95% confidence interval [CI] = 1.45-8.87; for the CDC/AAP definition: adjusted OR = 2.61, 95% CI = 1.08-6.28). Periodontal inflammation assessed by PISA was also significantly associated with a higher OR for MCI (adjusted OR = 1.05, 95% CI = 1.01-1.10, per 10-mm2 increase in PISA). CONCLUSION: Severe periodontitis and periodontal inflammation were associated with incident MCI among older community-dwelling men and women.

Amok: a mirror of time and people. A historical review of literature.

The conceptualization of psychiatric disorders changes continuously. This study examined 'amok', a culture-bound syndrome related to sudden mass homicide, to elucidate changing and varied concepts. A historical review of 88 English articles revealed that the meanings and assumed causes of amok have changed over time. These changes appear to have been affected by social events, medical discoveries, knowledge of descriptors and occasionally, the benefit to users. In other words, the concept of amok changes depending on the history of society and the knowledge and intention of people at the time. We should consider in detail what we focus on when diagnosing a disorder.

Arterial stiffness, not systolic blood pressure, increases with age in native Papuan populations.

Systolic blood pressure (SBP) and arterial stiffness are closely related and may behave reciprocally as cause or effect, interacting in a vicious cycle. Both SBP and arterial stiffness increase with age in populations in most developed countries. However, the age-related increase in SBP appears to be absent in indigenous populations, partially because of their lifelong low-sodium and high-potassium diets, whereas age-related arterial stiffening in these populations remains to be determined. We performed a field survey of the indigenous population of Soroba, a small village located in the central highlands of Papua, Indonesia. Blood pressure levels and brachial-ankle pulse wave velocity (baPWV) were measured using an automatic device. A total of 125 native Papuans 16-75 years of age (59% women) were included in this study. SBP and pulse pressure were not correlated with age. However, diastolic and mean arterial pressure levels increased with age. The prevalence of hypertension was 5% (n = 6; all women), and baPWV significantly increased with age. Compared with participants 45 years of age and older, those younger than 45 years had a higher body mass index (BMI) and spot urine sodium-to-potassium ratio but lower baPWV; however, SBP was not different between these age groups. Multivariate linear regression analysis revealed that SBP was independently associated with baPWV, sex and BMI but not with age; baPWV was independently associated with SBP, age, BMI, sex and heart rate. SBP and baPWV were closely related, but the age-related changes in these measurements differed in this highland Papuan population.

Association between objectively measured chewing ability and frailty: A cross-sectional study in central Thailand.

AIM: Limited data are available on the association between oral function and frailty, especially in developing countries. Additionally, the association between objectively assessed chewing function and frailty has not been well studied. The present cross-sectional study tested the hypothesis that objectively measured poor chewing ability is associated with frailty in community-dwelling older Thai adults. METHODS: The study population comprised 141 people in Nakhon Pathom, Thailand (median age 72 years). Demographic and clinical data were collected at a community center. Participants were asked to chew a gum designed for assessing chewing ability. The differences in gum color before and after chewing (ΔE*ab) were calculated and used as the exposure variable, where a lower ΔE*ab indicates lower chewing ability. Frailty phenotypes were defined by weakness, slowness, weight loss, low physical activity level and exhaustion components, and used as the outcome variable. Participants with three or more components were considered frail, and those with one or two components were considered pre-frail. Ordinal logistic regression analyses were carried out to assess the association of objective chewing ability with frailty. RESULTS: Of the 141 participants, 32 (22.7%) were categorized as frail and 78 (55.3%) as pre-frail. In the analysis adjusted for demographic and health characteristics, the adjusted odds ratio of the presence and severity of frailty was significantly higher in participants with lower ΔE*ab (adjusted odds ratio for one decrease in ΔE*ab 1.05, 95% confidence interval 1.01-1.10, P = 0.03). CONCLUSIONS: Objectively measured chewing ability was significantly associated with frailty in community-dwelling older Thai adults. Geriatr Gerontol Int 2018; 18: 860-866.

Self-rated health is associated with subsequent functional decline among older adults in Japan.

BACKGROUND: Previous studies have reported that self-rated health (SRH) predicts subsequent mortality. However, less is known about the association between SRH and functional ability. The aim of this study was to examine whether SRH predicts decline in basic activities of daily living (ADL), even after adjustment for depression, among community-dwelling older adults in Japan. METHODS: A three-year prospective cohort study was conducted among 654 residents aged 65 years and older without disability in performing basic ADL at baseline. SRH was assessed using a visual analogue scale (range; 0-100), and dichotomized into low and high groups. Information on functional ability, sociodemographic factors, depressive symptoms, and medical conditions were obtained using a self-administered questionnaire. Logistic regression analysis was used to examine the association between baseline SRH and functional decline three years later. RESULTS: One hundred and eight (16.5%) participants reported a decline in basic ADL at the three-year follow-up. Multiple logistic regression analysis showed that the low SRH group had a higher risk for functional decline compared to the high SRH group, even after controlling for potential confounding factors (odds ratio (OR) = 2.4; 95% confidence interval (CI) = 1.3-4.4). Furthermore, a 10-point difference in SRH score was associated with subsequent functional decline (OR = 1.37; 95% CI = 1.16-1.61). CONCLUSIONS: SRH was an independent predictor of functional decline. SRH could be a simple assessment tool for predicting the loss or maintenance of functional ability in community-dwelling older adults. Positive self-evaluation might be useful to maintain an active lifestyle and stay healthy.

Sleep quality among elderly high-altitude dwellers in Ladakh.

It has been already known that people who temporarily stay at high altitude may develop insomnia as a symptom of acute mountain sickness. However, much less is known about people living at high altitude. The aim of this study was to determine the effect of high altitude environment on sleep quality for the elderly who have been living at high altitude for their whole lives. A cross-sectional study was conducted in Domkhar valley at altitudes of 2800-4200m, Ladakh. Sleep quality was assessed using Insomnia Severity Index (ISI). Measurement items include body mass index, blood pressure, blood sugar, hemoglobin, timed Up and Go test, oxygen saturation during wakefulness, respiratory function test, Oxford Knee Score (OKS), and Geriatric Depression Scale (GDS), and so on. The participants were Ladakhi older adults aged 60 years or over (n=112) in Domkhar valley. The participation rate was 65.1% (male: female=47:65, mean age: 71.3 years and 67.9 years, respectively). The prevalence of the high score of ISI (8 or more) was 15.2% (17 out of 112). Altitude of residence was significantly correlated with ISI. Stepwise multiple regression analysis showed that OKS and altitude of residence were significantly related with ISI.

Health and happiness among community-dwelling older adults in Domkhar valley, Ladakh, India.

AIM: The aim of the present study was to show the status of objective geriatric functions and subjective quality of life in Ladakh, India, compared with Japanese controls. METHODS: We analyzed data of 117 people aged 60 years or older in Domkhar, and age- and sex-specific Japanese controls. Variables measured included blood pressure, hemoglobin, timed up & go test, basic activities of daily living, Geriatric Depression Scale and the Visual Analog Scale for subjective quality of life. RESULTS: People in Domkhar were more likely to have difficulties in basic activities of daily living compared with Japanese controls. However, they were significantly more likely to maintain social roles. The Visual Analog Scale scores in subjective friendship, economic satisfaction and happiness were higher in Domkhar compared with Japanese controls. Living alone (OR 9.92, 95% CI 2.13-46.26), high Geriatric Depression Scale score (6 or more; OR 8.45, 95% CI 1.65-43.35) and timed up & go test (17 s or more; OR 21.00, 95% CI 1.69-260.87) were significantly associated with a low score of subjective happiness (less than 50). Residence in Domkhar (OR 0.17, 95% CI 0.04-0.77) was a significant factor for low prevalence of a low score of subjective happiness by multivariate logistic regression analysis. CONCLUSIONS: Subjective quality of life among older adults in Domkhar was higher than Japanese controls despite a higher rate of difficulty in basic activities of daily living. We have to consider prevention, treatment, and care of not only diseases and disabilities, but also loneliness for the older adults. Geriatr Gerontol Int 2017; 17: 480-486.

Glucose intolerance associated with hypoxia in people living at high altitudes in the Tibetan highland.

OBJECTIVES: To clarify the association between glucose intolerance and high altitudes (2900-4800 m) in a hypoxic environment in Tibetan highlanders and to verify the hypothesis that high altitude dwelling increases vulnerability to diabetes mellitus (DM) accelerated by lifestyle change or ageing. DESIGN: Cross-sectional epidemiological study on Tibetan highlanders. PARTICIPANTS: We enrolled 1258 participants aged 40-87 years. The rural population comprised farmers in Domkhar (altitude 2900-3800 m) and nomads in Haiyan (3000-3100 m), Ryuho (4400 m) and Changthang (4300-4800 m). Urban area participants were from Leh (3300 m) and Jiegu (3700 m). MAIN OUTCOME MEASURE: Participants were classified into six glucose tolerance-based groups: DM, intermediate hyperglycaemia (IHG), normoglycaemia (NG), fasting DM, fasting IHG and fasting NG. Prevalence of glucose intolerance was compared in farmers, nomads and urban dwellers. Effects of dwelling at high altitude or hypoxia on glucose intolerance were analysed with the confounding factors of age, sex, obesity, lipids, haemoglobin, hypertension and lifestyle, using multiple logistic regression. RESULTS: The prevalence of DM (fasting DM)/IHG (fasting IHG) was 8.9% (6.5%)/25.1% (12.7%), respectively, in all participants. This prevalence was higher in urban dwellers (9.5% (7.1%)/28.5% (11.7%)) and in farmers (8.5% (6.1%)/28.5% (18.3%)) compared with nomads (8.2% (5.7%)/15.7% (9.7%)) (p=0.0140/0.0001). Dwelling at high altitude was significantly associated with fasting IHG+fasting DM/fasting DM (ORs for >4500 and 3500-4499 m were 3.59/4.36 and 2.07/1.76 vs <3500 m, respectively). After adjusting for lifestyle change, hypoxaemia and polycythaemia were closely associated with glucose intolerance. CONCLUSIONS: Socioeconomic factors, hypoxaemia and the effects of altitudes >3500 m play a major role in the high prevalence of glucose intolerance in highlanders. Tibetan highlanders may be vulnerable to glucose intolerance, with polycythaemia as a sign of poor hypoxic adaptation, accelerated by lifestyle change and ageing.