EbolaTracks: an automated SMS system for monitoring persons potentially exposed to Ebola virus disease.

We report development and implementation of a short message service (SMS)-based system to facilitate active monitoring of persons potentially exposed to Ebola virus disease (EVD), whether returning from EVD-affected countries, or contacts of local cases, should they occur. The system solicits information on symptoms and temperature twice daily. We demonstrated proof-of-concept; however this system would likely be even more useful where there are many local contacts to confirmed EVD cases or travellers from EVD-affected countries.

An outbreak of Cyclospora infection on a cruise ship.

In 2010, an outbreak of cyclosporiasis affected passengers and crew on two successive voyages of a cruise ship that departed from and returned to Fremantle, Australia. There were 73 laboratory-confirmed and 241 suspected cases of Cyclospora infection reported in passengers and crew from the combined cruises. A case-control study performed in crew members found that illness was associated with eating items of fresh produce served onboard the ship, but the study was unable conclusively to identify the responsible food(s). It is likely that one or more of the fresh produce items taken onboard at a south-east Asian port during the first cruise was contaminated. If fresh produce supplied to cruise ships is sourced from countries or regions where Cyclospora is endemic, robust standards of food production and hygiene should be applied to the supply chain.

Secondary attack rate of pandemic influenza A(H1N1) 2009 in Western Australian households, 29 May-7 August 2009.

Understanding household transmission of the pandemic influenza A(H1N1)2009 virus, including risk factors for transmission, is important for refining public health strategies to reduce the burden of the disease. During the influenza season of 2009 we investigated transmission of the emerging virus in 595 households in which the index case was the first symptomatic case of influenza A(H1N1)2009. Secondary cases were defined as household contacts with influenza-like illness (ILI) or laboratory-confirmed influenza A(H1N1)2009, occurring at least one day after but within seven days following symptom onset in the index case. ILI developed in 231 of the 1,589 household contacts, a secondary attack rate of 14.5% (95% confidence interval (CI): 12.9­16.4). At least one secondary case occurred in 166 of the 595 households (a household transmission rate of 27.9%; 95% CI: 24.5­31.6).Of these, 127 (76.5%) households reported one secondary case and 39 (23.5%) households reported two or more secondary cases. Secondary attack rates were highest in children younger than five years (p=0.001), and young children were also more efficient transmitters (p=0.01). Individual risk was not associated with household size. Prophylactic antiviral therapy was associated with reduced transmission (p=0.03). The secondary attack rate of ILI in households with a confirmed pandemic influenza A(H1N1)2009 index case was comparable to that described previously for seasonal influenza.

Association between 2009 seasonal influenza vaccine and influenza-like illness during the 2009 pandemic: preliminary results of a large household transmission study in Western Australia.

We conducted a prospective household transmission study to examine whether receipt of 2009 trivalent influenza vaccine (TIV) was associated with increased risk of influenza-like illness (ILI) among contacts of confirmed pandemic influenza A(H1N1) 2009 patients. In the week following onset of pandemic illness in a household member, 46 (15%) of 304 TIV-vaccinated contacts, and 174 (15%) of 1,162 unvaccinated contacts developed ILI (p=0.95). Receipt of 2009 TIV had no effect on one's risk of pandemic illness.

Verification of measles elimination in Australia: Application of World Health Organization regional guidelines.

BACKGROUND: The World Health Organization (WHO) Western Pacific Region (WPR) Guidelines on verification of measles elimination were established in 2012. This article outlines Australia's approach to addressing the guideline's five lines of evidence, which led to formal verification of elimination by the WHO Regional Verification Commission (RVC) in March 2014. METHODS: The criteria were addressed using national measles notifications, data from selected laboratories, the national childhood immunization register, and three national serosurveys (1998/1999, 2002, 2007). RESULTS: Australia met or exceeded all indicator targets with either national or sentinel data. Laboratory and epidemiological surveillance were of high quality, with 85% of cases documented as imported/import-related (target 80%); coverage with the first dose of measles vaccine was close to 94% in 2008-2012 and second dose coverage increased to 91% in 2012 (target >95%). There is ongoing commitment by the Australian Government to increase immunization coverage, and the absence of sustained transmission of any single measles genotype was demonstrated. CONCLUSIONS: This is the first documentation of the successful application of the WPR RVC guidelines. The indicators afford some flexibility but appear to provide appropriate rigor to judge achievement of measles elimination. Our experience could assist other countries seeking to verify their elimination status.

Insulin levels and the natural history of glucose intolerance in Nauruans.

Longitudinal changes in serum insulin concentrations in relation to the natural history of glucose intolerance and factors associated with the incidence of NIDDM were studied in 838 nondiabetic Micronesian Nauruans over the 5.1-year period from 1982 to 1987. In 13 individuals who had data at three time-points and who developed NIDDM only at the final test, 2-h insulin levels followed an inverted V-shaped pattern as glucose tolerance declined to NIDDM. Subjects who were normal (n = 651) or had impaired glucose tolerance (IGT) (n = 187) at the 1982 baseline survey were divided into six natural history categories depending on glucose tolerance in 1987. Changes in glucose tolerance were accompanied by changes in mean 2-h insulin concentration that paralleled the inverted V pattern seen in the 13 individuals. Longitudinal changes in fasting insulin were less consistent, but mean levels increased as subjects developed NIDDM. The 5.1-year incidence of NIDDM was strongly related to baseline fasting and 2-h glucose concentrations, but associations with insulin levels were weak and inconsistent. Neither fasting nor 2-h insulin concentrations contributed to logistic regression models predicting deterioration in glucose tolerance, whereas fasting and 2-h glucose levels were included in all models and BMI also predicted deterioration from normal. These data showing sequential changes in insulin concentrations support the beta-cell exhaustion theory of NIDDM pathogenesis. However, in contrast to glucose concentrations and obesity, insulin levels are poor predictors of NIDDM risk in Nauruans. This reflects the complexity of interactions with other metabolic markers and the inability of a single examination to characterize the point along the inverted V curve of insulin secretion that an individual has reached.

Prevalence and risk factors for micro- and macroalbuminuria in diabetic subjects and entire population of Nauru.

Rates of elevated urinary albumin concentration, defined as microalbuminuria (30-299 micrograms/ml) and macroalbuminuria (greater than or equal to 300 micrograms/ml), were determined on random morning urine specimens in the population of Nauru, which has a high prevalence of non-insulin-dependent diabetes mellitus. The prevalence of elevated urinary albumin levels in the total Nauruan population was very high: 26 and 30% of men and women, respectively, had microalbuminuria, whereas 13% of both sexes had macroalbuminuria. Of the subjects with macroalbuminuria, 66% had diabetes. The prevalence increased with worsening glucose tolerance; 26% of subjects with normal glucose tolerance had either micro- or macroalbuminuria, increasing to 43% of subjects with impaired glucose tolerance, 63% of newly diagnosed diabetic subjects, and 75% of previously diagnosed diabetic subjects. Associations between elevated urinary albumin concentration and putative risk factors were assessed for both the total population (n = 1184) and the diabetic subgroup alone (n = 318). Fasting plasma glucose and hypertension were the most important independent correlates for the whole population, whereas plasma creatinine was also important in diabetic subjects. Age at onset and duration of diabetes were not found to be significantly associated with elevated albumin concentration. In subjects with normal glucose tolerance, hypertension and hyperuricemia were the most important associated factors. These results suggest that blood glucose, blood pressure, and possibly obesity and plasma uric acid are important modifiable risk factors for both micro- and macroalbuminuria in this population.

High prevalence of NIDDM and impaired glucose tolerance in Indian, Creole, and Chinese Mauritians. Mauritius Noncommunicable Disease Study Group.

Mauritius, a multiethnic island nation in the southwestern Indian Ocean, has one of the world's highest diabetes mortality rates. The prevalence of both impaired glucose tolerance (IGT) and non-insulin-dependent diabetes mellitus (NIDDM) was investigated in 5080 Muslim and Hindu Indian, Creole (mixed African, European, and Indian origin), and Chinese Mauritian adults aged 25-74 yr who were selected by random cluster sampling. Based on a 75-g oral glucose tolerance test and World Health Organization criteria, the age-standardized prevalence of IGT was significantly greater in women (19.7%, 95% confidence interval [CI] 18.1-21.2) than in men (11.7%, CI 10.5-12.8). By contrast, the prevalence of NIDDM was similar in men (12.1%, CI 10.9-13.4) and women (11.7%, CI 10.5-12.8) for all ethnic groups combined. The sex difference in IGT prevalence was seen in all ethnic groups, but for NIDDM, the sex difference was not consistent across ethnic groups. However, age- and sex-standardized prevalence of IGT and NIDDM was remarkably similar across ethnic groups (16.2 and 12.4% in Hindu Indians, 15.3 and 13.3% in Muslim Indians, 17.5 and 10.4% in Creoles, and 16.6 and 11.9% in Chinese, respectively). Three new cases of diabetes were diagnosed for every two known cases. The high prevalence of abnormal glucose tolerance in Indian subjects is consistent with studies of other migrant Indian communities, but the findings in Creole and, in particular, Chinese subjects are unexpected. Potent environmental factors shared between ethnic groups in Mauritius may be responsible for the epidemic of glucose intolerance.

Predictors of progression from impaired glucose tolerance to NIDDM: an analysis of six prospective studies.

Risk factors associated with the progression from impaired glucose tolerance (IGT) to NIDDM were examined in data from six prospective studies. IGT and NIDDM were defined in all studies by World Health Organization (WHO) criteria, and baseline risk factors were measured at the time of first recognition of IGT. The studies varied in size from 177 to 693 participants with IGT, and included men and women followed from 2 to 27 years after the recognition of IGT. Across the six studies, the incidence rate of NIDDM was 57.2/1,000 person-years and ranged from 35.8/1,000 to 87.3/1,000 person-years. Although baseline measures of fasting and 2-h postchallenge glucose levels were both positively associated with NIDDM incidence, incidence rates were sharply higher for those in the top quartile of fasting plasma glucose levels, but increased linearly with increasing 2-h postchallenge glucose quartiles. Incidence rates were higher among the Hispanic, Mexican-American, Pima, and Nauruan populations than among Caucasians. The effect of baseline age on NIDDM incidence rates differed among the studies; the rates did not increase or rose only slightly with increasing baseline age in three of the studies and formed an inverted U in three studies. In all studies, estimates of obesity (including BMI, waist-to-hip ratio, and waist circumference) were positively associated with NIDDM incidence. BMI was associated with NIDDM incidence independently of fasting and 2-h post challenge glucose levels in the combined analysis of all six studies and in three cohorts separately, but not in the three studies with the highest NIDDM incidence rates. Sex and family history of diabetes were generally not related to NIDDM progression. This analysis indicates that persons with IGT are at high risk and that further refinement of risk can be made by other simple measurements. The ability to identify persons at high risk of NIDDM should facilitate clinical trials in diabetes prevention.

Relationship between prevalence of impaired glucose tolerance and NIDDM in a population.

OBJECTIVE: To study the relationship between the prevalence of impaired glucose tolerance (IGT) and non-insulin-dependent diabetes mellitus (NIDDM) across populations of the Pacific Ocean region to assess whether variability in those two proportions followed some predictable pattern related to modernization of life-style and risk factor levels. RESEARCH DESIGN AND METHODS: Prevalence estimates from studies with 75-g oral glucose loads and World Health Organization criteria were age standardized. RESULTS: The linear correlation between IGT and NIDDM prevalence was poor (0.22 in men and 0.24 in women), although it was improved when the outlying data of Micronesian Nauruans and Australian Aborigines were excluded (r = 0.65, P less than 0.01 in men and r = 0.54, P less than 0.01 in women). However, an epidemicity index calculated as the percentage of total glucose intolerance (TGI) made up by IGT (i.e., IGT/TGI) had the strongest correlation with NIDDM prevalence (r = -0.81, P less than 0.001 in men and r = -0.77, P less than 0.001 in women) and also explained more of its variance, with no population having undue influence on the relationship. When IGT/TGI was plotted against NIDDM prevalence for the genetically homogeneous rural (relatively traditional) and urban (modernized) segments of five Pacific island populations, there was a clear tendency for IGT/TGI to decline as the prevalence of NIDDM increased in association with worsening risk factor levels. However, longitudinal data for the high prevalence population of Nauru demonstrated that at least in a stabilizing epidemic, changes in the prevalence of IGT and NIDDM may not be easily predictable. CONCLUSIONS: The epidemicity index may be useful as an indicator of the potential for higher future NIDDM prevalence in whole populations. Populations will probably equilibrate at a certain NIDDM prevalence dependent on the strength of their genetic susceptibility to the disease and their degree of exposure to adverse environmental risk factors, including modern diet, physical inactivity, and obesity.

Evidence against association between parity and NIDDM from five population groups.

OBJECTIVE: To determine whether a reported positive association between parity and the development of non-insulin-dependent diabetes mellitus (NIDDM) and impaired glucose tolerance (IGT) is reproducible in other populations. RESEARCH DESIGN AND METHODS: We investigated the relationship in data from population-based surveys in four Pacific and Indian Ocean island nations. Women greater than or equal to 40 yr of age at the time of the survey, excluding those in whom diabetes developed before 40 yr of age, were included in this study of Micronesians from Nauru (n = 204) and Kiribati (n = 562), Fiji Melanesians (n = 390), Fiji Indians (n = 247), and mixed-ethnic Mauritians (n = 1333). Subjects in each survey underwent a 75-g oral glucose tolerance test, and glucose tolerance status was ascertained with 1985 World Health Organization criteria. Obstetric information and family history of diabetes were determined by interview. RESULTS: Age and body mass index (BMI)-adjusted mean parity increased slightly with worsening glucose tolerance in only two groups, decreased in one group, and was inconsistent in the other two (none were statistically significant). We also found an inconsistent relationship between the number of full-term pregnancies and the prevalence of IGT and NIDDM, although in each population, there was a higher prevalence of NIDDM in the highest parity group (greater than or equal to 10 pregnancies) compared with the lowest parity group (1-3 pregnancies). In logistic regression analyses accounting for age, BMI, and family history of diabetes, odds ratio estimates for NIDDM and IGT associated with each pregnancy were not significantly greater than unity. CONCLUSIONS: The results indicate that there is little if any independent association between parity and the development of abnormal glucose tolerance in these populations.

Diabetes and nontraumatic lower extremity amputations. Incidence, risk factors, and prevention--a 12-year follow-up study in Nauru.

OBJECTIVE: To measure the 12-year incidence (1982-1994) of nontraumatic lower extremity amputations (LEAs) in Nauruans, a population at high risk for NIDDM, and to determine the risk factors for amputation in Nauruans with diabetes. RESEARCH DESIGN AND METHODS: Amputation data were abstracted from operating theater records in Nauru, hospital databases in Australia, and Nauru government records. Baseline characteristics of a cohort of 1,564 Nauruans aged > or = 20 years examined during a population-based survey in 1982 were used to determine risk factors for first LEAs. RESULTS: Over this 12-year period, 46 first LEAs were performed on people with NIDDM, of whom 30 were members of the 1982 study cohort. The incidence of first LEAs in Nauruans aged > or = 25 years with NIDDM was 8.1 per 1,000 person-years in the study cohort and an estimated 7.6 per 1,000 person-years nationally. Amputations were associated significantly with lower BMI, lower blood pressure, higher fasting plasma glucose (FPG) level, and longer mean duration of diabetes at baseline, but levels of other risk factors, including cigarette smoking, plasma triglycerides, and plasma cholesterol, were also elevated in amputees. There were no amputations among individuals with baseline FPG levels < 7.8 mmol/l, irrespective of diabetes duration. FPG, baseline diabetes duration, and male sex were independent risk factors for first amputation using the Cox proportional hazards model. There was a decrease in the incidence of amputations after the commencement of a national foot care health education and prevention campaign in June 1992. CONCLUSIONS: The incidence of LEAs in diabetic Nauruans was higher than in other populations after adjusting for age and duration. Given the apparent success of the Nauruan footcare program in reducing amputation rates, other populations with high rates of NIDDM and LEAs should consider population-wide prevention strategies.

A case-control study of diet in newly diagnosed NIDDM in the Wanigela people of Papua New Guinea.

OBJECTIVE--To study the association between diet and newly diagnosed NIDDM in the Wanigela people of Papua New Guinea, a population with an extraordinary susceptibility for NIDDM. RESEARCH DESIGN AND METHODS--We performed a case-control study of Wanigela people from an urban settlement (Koki). Case patients (n = 145) were asymptomatic subjects in whom NIDDM was newly diagnosed using a 2-h 75-g oral glucose tolerance test. Control subjects with glucose tolerance (n = 140) were group-matched on the basis of age and sex. A detailed food frequency questionnaire was used to determine energy and nutrient intakes. Nutrient intakes were compared directly and after calculation of residuals to correct for energy intake. Odds ratios for NIDDM were computed in relation to total energy and specific nutrient intakes, adjusting for age, sex, BMI, waist-to-hip ratio, and physical activity. RESULTS--There were no differences between case patients and control subjects in mean values of total energy-adjusted nutrient intakes. In logistic regression models, neither total energy nor any specific nutrients were associated with increased risk of NIDDM. When models were repeated with nutrients categorized by textiles, there were marginally significant associations with intakes of fiber (positive) and cholesterol, protein, and sugar (negative). CONCLUSIONS--This study does not support the hypothesis that saturated fat is an independent risk factor for NIDDM. The weak associations of intakes of fiber and cholesterol with newly diagnosed NIDDM were in the opposite directions to those expected and are probably due to chance. Relative homogeneity of diet within a community, such as that found in Koki, makes it difficult to demonstrate risk factor-disease associations. However, changes in diet and reduced levels of physical activity accompanying urbanization undoubtedly contribute to the high prevalence of obesity observed in this community, and hence diet is likely to contribute to NIDDM risk at least by indirect means.

Increasing prevalence of NIDDM in the Pacific island population of Western Samoa over a 13-year period.

OBJECTIVE: A survey of noncommunicable diseases (NCD) in the Pacific island population of Western Samoa in 1978 (n = 1,206) documented a relatively high prevalence of non-insulin-dependent diabetes mellitus (NIDDM) and obesity. A follow-up survey was performed in 1991 (n = 1,776) to assess changes in NCD prevalence and risk factor distribution over 13 years. RESEARCH DESIGN AND METHODS: In both surveys, the same representative villages from one urban and two rural areas were studied, and the survey procedure included an oral glucose tolerance test, anthropometric and blood pressure measurements, and physical activity assessment (1991 only). RESULTS: The age-standardized prevalence of NIDDM in 1991 was 9.5 and 13.4% in Apia (urban) for men and women, respectively. In Poutasi (rural), 5.3% of men and 5.6% of women had NIDDM, and in Tuasivi (rural) the prevalence was 7.0 and 7.5% for men and women, respectively. Age, body mass index (BMI), waist-to-hip circumference ratio, physical inactivity, and family history of diabetes all showed independent association with NIDDM and impaired glucose tolerance. Living in Apia (compared with Poutasi) was also associated with NIDDM. Between 1978 and 1991, the age-standardized prevalence of NIDDM in Apia increased from 8.1 to 9.5% in men and 8.2 to 13.4% in women. In Poutasi, a dramatic increase occurred in prevalence from 0.1 to 5.3% in men, but little change in women was noted (5.4 to 5.6%). In Tuasivi, the increases were 2.3 to 7.0% in men and 4.4 to 7.5% in women. In combined survey areas, increases were observed in the age-standardized prevalence of obesity and mean levels of total cholesterol, fasting triglycerides, and uric acid between surveys as well as a reduction in the prevalence of smoking. CONCLUSIONS: This is the first study using standardized methods to show a dramatic increase in the prevalence of NIDDM in a developing Pacific island population, and it indicates the importance of maintaining and expanding preventive programs for NIDDM and related lifestyle diseases in these populations.

Abdominal obesity and physical inactivity as risk factors for NIDDM and impaired glucose tolerance in Indian, Creole, and Chinese Mauritians.

OBJECTIVE: We wanted to determine whether obesity, abdominal fat distribution, and physical inactivity act similarly and independently as risk factors for noninsulin-dependent diabetes mellitus (NIDDM) and impaired glucose tolerance (IGT) in Hindu and Muslim Asian Indians, African-origin Creoles, and Chinese Mauritians. RESEARCH DESIGN AND METHODS: We examined a population-based random cluster sample of 5080 adult subjects from the Indian Ocean island of Mauritius. Glucose tolerance was assessed with a 75-g oral glucose tolerance test and World Health Organization criteria. RESULTS: Univariate data and multiple logistic regression models indicated that age, family history of diabetes, body mass index (BMI), waist-hip ratio (WHR), and physical inactivity conveyed similar risk for NIDDM (and IGT) in each ethnic group. After adjusting for all other factors, Hindu ethnicity conferred additional risk for NIDDM (but not IGT) in men, but in women there were no clear ethnic differences. Although BMI and WHR were independently significant risk factors, WHR conveyed relatively stronger risk for NIDDM than BMI in women, whereas the converse was true in men. For ethnic groups combined, the independent odds ratios for IGT associated with moderate and low physical activity scores (relative to high) were 1.56 and 1.71 (P less than 0.05), respectively, in men and 1.32 and 1.69 (P less than 0.05) in women. In subjects with asymptomatic NIDDM diagnosed during the survey, the independent odds ratios were 1.96 and 2.00 (P less than 0.05) in men and 1.73 and 2.70 (P less than 0.05) in women. CONCLUSIONS: These data indicate that BMI, abdominally distributed fat, and physical inactivity are important independent risk factors for both IGT and NIDDM in diverse ethnic groups. Attributable risk fractions for Mauritius suggest that populationwide modification of levels of these risk factors could potentially result in substantially lower occurrence of NIDDM (and IGT). Such interventions should be attempted in high-risk populations.

Incidence of IDDM in Mauritian children and adolescents from 1986 to 1990.

OBJECTIVE: To document the incidence of IDDM in Mauritian children and adolescents 0-19 yr of age from 1986 to 1990. RESEARCH DESIGN AND METHODS: We used a population-based register that used pediatricians, physicians, nutritionists, and general practitioners as a primary source of retrospective case ascertainment. The denominator data were obtained from the Statistics Office of the Ministry of Health (Port Louis, Mauritius). RESULTS: In 1990, 37 newly diagnosed IDDM cases (22 females and 15 males) were identified between 1986 and 1990 among the population < or = 19 yr of age. The average incidence density per year was 1.9/100,000 people and was slightly higher among girls (2.2/100,000) than among boys (1.5/100,000). The average age-standardized incidence density was 2.1/100,000 people (95% confidence interval 1.5-3.0) among children < or = 14 yr of age, 2.5/100,000 people (95% confidence interval 1.5-3.9) among girls, and 1.8/100,000 people (95% confidence interval 1.0-3.0) among boys. The incidence was similarly low in Mauritians of Asian Indian, Chinese, and Creole (predominantly African) origin. CONCLUSIONS: The incidence of IDDM in Mauritian children and adolescents is among the lowest yet reported. This sharply contrasts with the very high risk of NIDDM found among the adult population in this rapidly modernizing country.

High prevalence of diabetic retinopathy and nephropathy in Polynesians of Western Samoa.

OBJECTIVE: To determine the prevalence of diabetic retinopathy and nephropathy retinopathy and nephropathy and to define associated risk factors in Polynesian Western Samoans with non-insulin-dependent diabetes mellitus (NIDDM) or impaired glucose tolerance (IGT). RESEARCH DESIGN AND METHODS: A 1991 population-based study in Samoan adults (ages 25-74 years) included a 75-g oral glucose tolerance test, anthropometric measurements, and blood pressure recordings. Subjects with NIDDM or IGT had 45-degree stereo photographs taken (n = 263) (three standard fields of the right eye), and retinopathy was graded in comparison with Airlie House photographs. First-morning urine samples (n = 304) were also collected from these subjects and from a subsample with normal glucose tolerance. Urinary albumin concentration (UAC) was measured by radioimmunoassay: microalbuminuria was defined as UAC of 30-299 micrograms/ml; and macroalbuminuria among subjects with Proliferative diabetic retinopathy was found in 4.5% of known diabetic subjects. The prevalence of elevated UAC was 15.0% in subjects with IGT, 26.0% in newly diagnosed diabetes subjects, and 23.4% in known diabetes subjects. For all diabetic subjects (n = 162), the factors independently associated with diabetic retinopathy (logistic regression) were duration of diabetes, fasting plasma glucose, and body mass index (inversely). Duration of diabetes, serum triglyceride concentrations, and systolic blood pressure were independently associated with elevated UAC in all diabetic subjects (n = 138), and fasting plasma glucose had borderline significance. CONCLUSIONS: Diabetic retinopathy and albuminuria are common in Polynesian Western Samoans. Duration of diabetes and level of glycemia were the most important associated factors. These data underline the need for cost-effective programs for the detection and early treatment of diabetes in Western Samoa and other developing populations with high susceptibility to NIDDM.

Impaired fasting glucose: how low should it go?

OBJECTIVE: Impaired fasting glucose (IFG) has been recently introduced as a stage of abnormal carbohydrate metabolism, but the evidence on which its glucose limits (fasting plasma glucose [FPG] 6.1-6.9 mmol/l) are based is not strong. The aim of this study was to determine if 6.1 mmol/l represents a clear cutoff in terms of the risk of future diabetes and in terms of elevated cardiovascular risk factor levels, and to examine the use of other lower limits of IFG. RESEARCH DESIGN AND METHODS: A population-based survey of the island of Mauritius was undertaken in 1987, with a follow-up survey 5 years later. On both occasions, an oral glucose tolerance test was performed and cardiovascular risk factors were measured. RESULTS: Data were available from 4,721 nondiabetic people at baseline, and from 3,542 at follow-up. At baseline, blood pressure, lipids, and obesity increased in a linear fashion with increasing FPG, with no evidence of a threshold effect. The risk of developing hypertension at follow-up was greater for those people with baseline FPG > or =6.1 mmol/l (P<0.001). The risk of developing diabetes at follow-up increased with increasing baseline FPG, but there was little evidence of a threshold near 6.1 mmol/l. CONCLUSIONS: Cardiovascular risk and risk of future diabetes increase continually with increasing FPG, and there is no threshold value on which to base a definition of IFG. If a lower limit of approximately 5.8 mmol/l is used, the category defines a group more similar to the group with impaired glucose tolerance, with regard to total prevalence and the risk of subsequent diabetes.

Impaired fasting glucose or impaired glucose tolerance. What best predicts future diabetes in Mauritius?

OBJECTIVE: To determine if impaired fasting glucose (IFG; fasting plasma glucose level 6.1-6.9 mmol/l) can predict future type 2 diabetes as accurately as does impaired glucose tolerance (IGT; 2-h plasma glucose level 7.8-11.0 mmol/l). RESEARCH DESIGN AND METHODS: A longitudinal population-based study was performed with surveys in 1987 and 1992 on the island of Mauritius, assessing diabetes status by the oral glucose tolerance test. A total of 3,717 subjects took part in both surveys. Of these subjects, 3,229 were not diabetic in 1987 and formed the basis of this study. RESULTS: At baseline, there were 607 subjects with IGT and 266 subjects with IFG. There were 297 subjects who developed diabetes by 1992. For predicting progression to type 2 diabetes, the sensitivity, specificity, and positive predictive values were 26, 94, and 29% for IFG and 50, 84, and 24% for IGT, respectively. Only 26% of subjects that progressed to type 2 diabetes were predicted by their IFG values, but a further 35% could be identified by also considering IGT. The sensitivities were 24% for IFG and 37% for IGT in men and 26% for IFG and 66% for IGT in women, respectively. CONCLUSIONS: These data demonstrate the higher sensitivity of IGT over IFG for predicting progression to type 2 diabetes. Screening by the criteria for IFG alone would identify fewer people who subsequently progress to type 2 diabetes than would the oral glucose tolerance test.

Insulin and blood pressure levels are not independently related in Mauritians of Asian Indian, Creole or Chinese origin. The Mauritius Non-communicable Disease Study Group.

OBJECTIVES: There is conflicting evidence of a link between circulating insulin concentrations and blood pressure. The aim of this study, therefore, was to investigate this relationship in a representative population sample of different ethnic groups. DESIGN: A cross-sectional study was performed, using a random cluster sample of 5080 adults aged 25-74 years from the Indian Ocean island of Mauritius. METHODS: Glucose tolerance was assessed with a 75-g oral glucose tolerance test. Hypertension and glucose tolerance were classified using World Health Organization criteria. Subjects known to have diabetes before the survey were excluded from these analyses, leaving 3104 Asian Indian, 1256 African-origin Creole and 384 Chinese subjects eligible for this study. RESULTS: There were statistically significant linear correlations between fasting and 2-h insulin and mean blood pressure in all sex-ethnic subgroups, except for Chinese men. However, after controlling for age and the body mass index, partial correlations were much reduced and remained significant only for fasting insulin in Indian men (r = 0.07, P < 0.01) and women (r = 0.09, P < 0.001) and 2-h insulin in Chinese women (r = 0.15, P < 0.05). After controlling for age and body mass index, mean fasting and 2-h insulin concentrations were not significantly different between hypertensive and normotensive subjects in any of 36 possible subgroups defined by ethnic group, gender or glucose tolerance (normal, impaired glucose tolerance or newly diagnosed diabetes). In both men and women with normal glucose tolerance (ethnic groups combined) there was no evidence of increasing systolic or diastolic blood pressure across quartiles of either fasting or 2-h serum insulin within any quartile of the body mass index. By contrast, at any given level of serum insulin there was a clear association between an increasing body mass index and increasing blood pressure, suggesting strongly that insulin is not the final pathway by which obesity influences blood pressure. CONCLUSIONS: This study of three ethnic groups does not support the hypothesis that the circulating insulin concentration is an independent determinant of blood pressure in populations.