Comorbid Diabetes and Depression among Older Adults - Prevalence, Correlates, Disability and Healthcare Utilisation

INTRODUCTION

The objectives of this current study were to: 1) examine the prevalence and correlates of diabetes mellitus (DM) among older adults (aged 60 years and above) in a multi-ethnic population; 2) examine the prevalence and correlates of comorbid DM and depression among them; and 3) assess the effect of comorbid depression on disability, cognition and healthcare utilisation.

MATERIALS AND METHODS

Data for the current study came from the Well-being of the Singapore Elderly (WiSE) study; a single phase, cross-sectional survey conducted among Singapore residents aged 60 years and above. A total of 2565 respondents completed the survey; depression was assessed using the Automated Geriatric Examination for Computer Assisted Taxonomy (AGECAT) while a diagnosis of DM was considered if respondents stated that a doctor had diagnosed them with DM.

RESULTS

DM was reported by 25.5% of the population. The prevalence of depression was significantly higher in those diagnosed with DM than those without DM (6% vs 3%). After adjusting for sociodemographic correlates, smoking and other chronic conditions, DM remained significantly associated with depression and subsyndromal depression. However, after including measures of functioning and cognitive impairment as covariates, DM was not significantly related to depression and subsyndromal depression. Those with comorbid DM and depression were more likely to be of Indian and Malay ethnicity, aged 75 to 84 years (versus 60 to 74 years) and widowed.

CONCLUSION

Given the significant association of certain sociodemographic groups with comorbid depression among those with DM, targeted interventions for prevention and early diagnosis in these groups should be considered.

Health Screening Behaviour among Singaporeans

INTRODUCTION

This study assessed the health screening behaviour of Singaporeans and evaluated factors associated with low uptake of screening tests.

MATERIALS AND METHODS

Data from the 2010 National Health Survey, which was conducted on Singapore citizens and permanent residents, was used in this analysis. Multivariate Cox regression was used to evaluate the relationship between sociodemographics and health screening behaviour for selected chronic diseases (hypertension, diabetes and hypercholesterolaemia) and cancers (cervical, breast and colorectal). National recommendations for age at which screening should be initiated and appropriate screening interval were used to define appropriate screening behaviour.

RESULTS

More respondents have had their last chronic disease screening done within the recommended time period compared to cancer screening. A total of 77.8%, 63.4% and 54.9% of the respondents had their last hypertension, diabetes and hypercholesterolaemia done within the recommended time period respectively, while less than 50% of the respondents had their cervical (45.8%), breast (32.9%) and colorectal (20.2%) cancer screenings done within the recommended time period. Respondents with higher household income or more years of education were more likely to have undergone screening within the recommended time period. Indians, who are at higher risk of chronic diseases such as diabetes and hypercholesterolaemia, were also more likely to have been screened. A total of 69.9% and 79.5% of the respondents with previously undiagnosed diabetes and hypertension had reported to have done diabetes and hypertension screenings respectively, within the recommended time period.

CONCLUSION

Sociodemographic factors that could be associated with a lower uptake of screening tests include: 1) low household income, 2) low education level, and 3) Malay ethnicity. Health promotion programmes and outreach to these groups can be enhanced to further improve screening uptake.

Design of a prognostic index score for metastatic nasopharyngeal carcinoma

The survival outcome of patients with systemic cancer differs significantly between individuals even within the same tumour type. We set out to illustrate this by analysing the factors determining survival in patients with metastatic disease from nasopharyngeal carcinoma (NPC) and to design a scoring system based on these prognostic factors. Patients referred between January 1994 and December 1999 were retrospectively analysed. Factors analysed included patient (age group, gender, performance status (BS) at diagnosis of metastases), disease (number of metastatic sites, specific metastatic sites, disease-free interval (DFI), metastases at presentation, presence of locoregional recurrence), and laboratory factors (leucocyte count, haemoglobin level, albumin level). Univariate and multivariable analyses were performed using the Cox proportion hazards model. A numerical score was derived from the regression coefficients of each independent prognostic variable. The prognostic index score (PIS) of each patient was calculated by totalling up the scores of each independent variable. Independently significant, negative prognostic factors were liver metastasis, lung metastasis, anaemia, poor PS, distant metastasis at initial diagnosis, and a DFI of <6 months. Three prognostic groups based on the PIS were obtained: (i) good risk (PIS=0-6); (ii) intermediate risk (7-10); (iii) poor risk (>or=11). The median survivals for these groups were 19.5, 10, and 5.8, months, respectively, (log rank test: P<0.0001). The variable prognosis of patients with disseminated NPC can be assessed by using easily available clinical information (patient, disease and laboratory factors). The PIS system will need to be validated on prospectively collected data of another cohort of patients.

Incidence of ischaemic heart disease and stroke in Chinese, Malays and Indians in Singapore: Singapore Cardiovascular Cohort Study

INTRODUCTION

This is the first prospective cohort study in Singapore to describe the incidence of ischaemic heart disease (IHD) and stroke among Chinese, Malays and Asian Indians.

MATERIALS AND METHODS

The Singapore Cardiovascular Cohort Study is a longitudinal follow-up study on a general population cohort of 5920 persons drawn from 3 previous cross-sectional surveys. Morbidity and mortality from IHD and stroke were ascertained by record linkage using a unique identification number with the death registry, Singapore Myocardial Infarct Registry and in-patient discharge databases.

RESULTS

There were 193 first IHD events and 97 first strokes during 52,806 person-years of observation. The overall incidence of IHD was 3.8/1000 person-years and that of stroke was 1.8/1000 person-years. In both males and females, Indians had the highest IHD incidence, followed by Malays and then Chinese. For males after adjusting for age, Indians were 2.78 times (95% CI 1.86, 4.17; P < 0.0001) and 2.28 times (95% CI 1.34, 3.88; P = 0.002) more likely to get IHD than Chinese and Malays respectively. For females after adjusting for age, Indians were 1.97 times (95% CI 1.07, 3.63; P = 0.03) and 1.37 times (95% CI 0.67, 2.80; P = 0.39) more likely to get IHD than Chinese and Malays respectively. For stroke, male Chinese and Indians had higher incidence than Malays (though not statistically significant). However, in females, Malays had the highest incidence of stroke, being 2.57 times (95% CI 1.31, 5.05; P = 0.008) more likely to get stroke than Chinese after adjustment for age.

CONCLUSIONS

This prospective study of both mortality and morbidity has confirmed the higher risk of IHD in Indians. It has also found that Malay females have a higher incidence of stroke, which deserves further study because of its potential public health importance.

A rational alternative for the diagnosis of diabetes mellitus in high risk individuals

INTRODUCTIONS

To facilitate early, accurate diagnosis, tests should be easy, cheap and reproducible. We studied volunteers with an increased risk of developing diabetes mellitus (DM) to see if HbA1c levels could replace the oral glucose tolerance test (OGTT) in diagnosing DM.

MATERIALS AND METHOD

One hundred and eleven individuals were studied, using the standard oral glucose tolerance test, and simultaneous measurement of HbA1c levels. Receiver operator characteristic (ROC) analysis was performed to assess the sensitivity and specificity of various HbA1c cut-off levels for diagnosing DM. The relationship between fasting plasma glucose (FPG) and DM diagnosis was also investigated.

RESULTS

The majority of DM and impaired glucose tolerance (IGT) cases were diagnosed on the basis of two-hour OGTT glucose values. If FPG alone had been used, 29% of the study population with DM or IGT would have been missed. HbA1c cut-off of 6.2% or 6.3% gives the optimal sensitivity and specificity. In linear regression analysis, FPG was found to be a significant predictor of 2-hour OGTT, but only accounted for 45% of the variability of 2-hour OGTT glucose value.

CONCLUSIONS

Our data support the view that although HbA1c alone cannot replace the OGTT in the diagnosis of DM, it can still provide a useful guide to rational, cost-effective screening for diabetes mellitus.

Prognostic factors in 677 patients in Singapore with nondisseminated nasopharyngeal carcinoma

BACKGROUND

The objective of the current study was to describe the survival of nasopharyngeal carcinoma (NPC) patients in Singapore, verify the prognostic value of the revised 1997 TNM staging system, and develop a multivariate prognostic model for NPC. In addition, the authors also examined the prognostic value of characteristics of lymph node spread and parapharyngeal involvement.

METHODS

A prospectively maintained database containing clinical and computed tomography scan data was used to reclassify 677 NPC patients treated between 1992 and 1994 according to the new staging system. Records were linked with the death registry to ascertain the patient's vital status and date of death. Overall and stage specific survival were analyzed using the Kaplan-Meier method and the log rank test. Univariate and multivariate Cox proportional hazards regression analysis were used to obtain prognostic models.

RESULTS

Two hundred seventy-four deaths (40.5%) occurred. The 5-year survival rate was 56.6% (95% confidence interval [95% CI], 52.3%, 60.7%). The stage specific 5-year survival rates were: Stage I, 88%; Stage IIA, 75%; Stage IIB, 74%; Stage III, 60%; Stage IVA, 35%; and Stage IVB, 28%. TNM stage was found to be a statistically significant prognostic factor (P < 0.0001). Cranial nerve (hazard ratio [HR]: 2.77), orbit (HR: 5.71), and intracranial involvement (HR: 2.46) conferred a particularly bad prognosis in univariate analysis. Independently significant prognostic factors were age; lymph node status; and paraoropharyngeal, cranial nerve, orbit, and nasal involvement. Among lymph node positive patients, independently significant prognostic lymph node characteristics were Ho level and laterality. Although parapharyngeal involvement appeared to be prognostically unimportant, paraoropharyngeal involvement distinguished a subgroup with a poorer prognosis (HR: 1.84; 95% CI, 1.45, 2.34; P < 0.0001). Lateral spread to the medial infratemporal fossa and beyond also was found to confer a poorer prognosis.

CONCLUSIONS

The results of the current study show that the revised 1997 TNM staging system is prognostically useful. Subdivision into paraoropharyngeal involvement and using the medial infratemporal fossa to delineate prognostically significant lateral spread should be considered in future revisions.

Ethnicity, obstructive sleep apnoea and ischaemic heart disease

We studied the relationship between different ethnic groups, obstructive sleep apnoea (OSA) and ischaemic heart disease. Four hundred and thirty-two inpatients from the medical wards were interviewed. Limited overnight sleep studies were done in 129 of those who had habitual snoring, daytime sleepiness based on an Epworth sleepiness scale of 8 or more, or a large neck size of 40 cm or more. There were 315 Chinese (72.9%), 67 Malays (15.5%), 43 Indians (10%) and 3 from other races (1.4%). The prevalence of OSA was 19.7%, 30% and 12% among the Chinese, Malays and Indians, respectively. The prevalence ratio for OSA was 1.52 in Malays using Chinese patients as the baseline (P = 0.07). The median neck circumference was 37 cm in both racial groups. The median body mass index was 22.7 kg/m2 in Chinese compared to 23.6 kg/m2 in Malays. The median apnoea-hypopnoea index was 22.7, 19.0 and 26.9 events/hour among the Chinese, Malays and Indians, respectively. OSA was independently associated with the prevalence of IHD (adjusted prevalence ratio 1.68; 95% CI: 1.15, 2.46; P = 0.009). The prevalence of ischaemic heart disease (IHD) was 31%, 24% and 28% in Chinese, Malays and Indians, respectively. The prevalence ratio for IHD in Malays compared to Chinese was 0.77. After adjusting for OSA, there was an even greater reduction in the risk of IHD (adjusted prevalence ratio 0.70). This suggests that OSA is a confounder in the relationship between race and ischaemic heart disease.