Methods for determining the amount of glucose in blood

Highlights of three metabolites HDL and reduction in blood pressure values after dietary fiber supplementation in overweight and obese normotensive women: a metabolomic study

INTRODUCTION

The prevalence of hypertension and obesity are a worldwide concern.

OBJETIVES

Assess the metabolites profile after intervention with mixed dietary fiber in overweight and obese normotensive women.

METHODS

This is a randomized double blind placebo-controlled study. Through a simple randomization process, two groups were allocated, with eleven women (group 1) receiving 12 g of mixed dietary fiber and thirteen women (group 2) receiving 12 g of placebo (corn starch) for eight weeks. Anthropometric and biochemical tests and lifestyle were analyzed. As for evaluation metabolomics, used a 1H NMR. The data matrix generated 96 samples and 225 variables, which was exported in the ASCII format for the "The Unscrumbler" statistics software (version 9.7, CAMO Process).

RESULTS

After the intervention with mixed dietary fiber, significant differences were observed between the main types of metabolites, referring to the increase in the relative peak areas of in three HDL metabolites 4.94 ppm (0.0086*), HDL 1.28 ppm (0 .0337*), HDL 0.88 ppm (0.0224*) and an α-glucose metabolite 4.90 ppm (0.0106) and the reduction in systolic blood pressure (SBP) (0.0292*) of 7 mmHg in the reference range and in the placebo group there was a reduction in SBP (0.0118*) of 4 mmHg and of a choline metabolite 3.65 ppm (0.0266*), which does not call into question the validity of these results in the literature.

CONCLUSION

The synergism of the functions of these statistically highlighted metabolites contributed to prevention the increase in SBP after fiber intervention in overweight and obese normotensive women.

The Association of the Potential Risk Factors and Nutrition Elements with Abortion and Calving Rates of Egyptian Buffaloes (Bubalus bubalis)

Simple Summary

The association of the risk factors, serum constituents related to abortion and calving rates were investigated. Multiparous buffaloes were less likely to abort and more likely to calving than primiparous. Dry buffaloes had lesser odds of abortion and were six times more likely to give birth than those lactating. Conversely, the sex of the fetus had no impact. In aborted animals, serum glucose and copper were higher, whereas urea, uric acid, total proteins, total cholesterol, phosphorus, magnesium and iron were lower than in normal pregnancy. This emphasizes that risk factors and serum constituents associated with abortion aid to construct suitable preventive measures to raise reproductive performance.

Abstract

The aim of the present study was to investigate risk factors, serum minerals, and metabolites associated with non-infectious abortion and calving rates of Egyptian buffaloes. Data were obtained from 364 pregnant buffaloes of different ages and parities over 7 years from 2014 to 2020. Body condition score (BCS) was a risk factor regarding abortion and calving; the thinnest buffaloes were more likely to abort and less likely to calving than those with body energy reserves. In comparison with the spring season, aborting probability decreased 49.7% the odds ratio (OR = 0.503), while the chance of calving increased 72.1% (OR = 1.721) during winter. The parity was another significant factor related to abortion and calving rates; multiparous buffaloes were less likely to abort and more likely to calving than primiparous. Dry buffaloes had 88.2% (OR = 0.118) lesser odds of abortion and six times (OR = 6.012) more likely to give birth than those lactating. The sex of the fetus was not a risk factor regarding abortion or calving. Other variables significantly associated with abortion rate were glucose and copper in the sera of aborted buffaloes were significantly higher (p < 0.05), and those of urea, uric acid, total protein, total cholesterol, phosphorus, magnesium and iron were significantly (p < 0.05) lower than a normal pregnancy. In conclusion, the present results emphasize that the identification of the risk factors, serum minerals and metabolites associated with fetus abortion of Egyptian buffalo may provide useful information, which assists to construct suitable preventive measures to raise reproductive performance.

α-Tocopherol influences glycaemic control and miR-9-3 DNA methylation in overweight and obese women under an energy-restricted diet: a randomized, double-blind, exploratory, controlled clinical trial

Background

Excess weight is a strong risk factor for the development of dysglycaemia. It has been suggested that changes in the metabolism microRNAs, small non-coding RNAs that regulate gene expression, could precede late glycaemic changes. Vitamin E in turn may exert important functions in methylation and gene expression processes. This study aimed to determine the effect of α-tocopherol on glycaemic variables and miR-9-1 and miR-9-3 promoter DNA methylation in overweight women.

Methods

A randomized, double-blind, exploratory, placebo-controlled study was conducted in overweight and obese adult women (n = 44) who ingested synthetic vitamin E (all-rac-α-tocopherol), natural source vitamin E (RRR-rac-α-tocopherol) or placebo capsules and were followed up for a period of 8 weeks. Supplemented groups also received dietary guidance for an energy-restricted diet. An additional group that received no supplementation and did not follow an energy-restricted diet was also followed up. The intervention effect was evaluated by DNA methylation levels (quantitative real-time PCR assay) and anthropometric and biochemical variables (fasting plasma glucose, haemoglobin A1C, insulin, and vitamin E).

Results

Increased methylation levels of the miR-9-3 promoter region (P < 0.001) and reduced haemoglobin A1C (P < 0.05) were observed in the natural source vitamin E group after intervention. Increased fasting plasma glucose was observed in the synthetic vitamin E group, despite the significant reduction of anthropometric variables compared to the other groups.

Conclusions

α-Tocopherol from natural sources increased methylation levels of the miR-9-3 promoter region and reduced haemoglobin A1C in overweight women following an energy-restricted diet. These results provide novel information about the influence of vitamin E on DNA methylation.

Trial registration

ClinicalTrials.gov, NCT02922491. Registered 4 October, 2016.

Electronic supplementary material

The online version of this article (10.1186/s12986-018-0286-7) contains supplementary material, which is available to authorized users.

Nondiabetic Glucometabolic Status and Progression of Aortic Stiffness: The Whitehall II Study

OBJECTIVE

Aortic stiffness is an important predictor of future morbidity and mortality. Diabetes is associated with increased aortic stiffness, but the importance of nondiabetic glucometabolic status for accelerated aortic stiffening is unclear. We tested the hypothesis that adverse glucometabolic status is associated with accelerated aortic stiffening in individuals without diabetes, independently of known risk factors for arterial stiffening.

RESEARCH DESIGN AND METHODS

Glucometabolic status and other cardiovascular risk factors were assessed at baseline in 2008-09, and carotid femoral pulse wave velocity (cfPWV) at baseline and follow-up in 2012-13, in 4,386 participants without diabetes of the Whitehall II Study.

RESULTS

The mean age of the cohort at cfPWV baseline was 60 years, and 74% were male. cfPWV increased from (mean ± SE) 8.30 ± 0.03 to 8.98 ± 0.04 m/s during 4 years of follow-up. At baseline, cfPWV was associated with fasting and 2-h postload glucose, HbA_1c, and HOMA-insulin resistance (HOMA-IR). HbA_1c and HOMA-IR were associated with progression of cfPWV after adjusting for physiological confounders and cardiovascular risk factors. A 1 SD higher HbA_1c and HOMA-IR were associated with greater increases in cfPWV (0.11 m/s per 5 years [95% CI 0.04, 0.18], P = 0.003 and 0.09 m/s per 5 years [0.01, 0.17], P = 0.03, respectively). Additional adjustment for BMI weakened the association with HOMA-IR but not with HbA_1c.

CONCLUSIONS

HbA_1c is independently associated with accelerated progression of aortic stiffness in individuals without diabetes. These findings suggest that long-term glucometabolic status, even in individuals without diabetes, could be an important target for preventative strategies against vascular aging.

Diurnal Cortisol Patterns, Future Diabetes, and Impaired Glucose Metabolism in the Whitehall II Cohort Study

CONTEXT

The hypothalamic pituitary-adrenal axis is thought to play a role in type 2 diabetes (T2D). However, evidence for an association between cortisol and future glucose disturbance is sparse.

OBJECTIVE

The aim was to examine the association of diurnal cortisol secretion with future T2D and impaired glucose metabolism in a community-dwelling population.

DESIGN

This is a prospective cohort study of salivary cortisol measured at the 2002-2004 clinical examination of the Whitehall II study, United Kingdom. We measured cortisol (nmol/l) from six saliva samples obtained over the course of a day: at waking, +30 minutes, +2.5 hours, +8 hours, +12 hours, and bedtime. Participants who were normoglycemic in 2002-2004 (phase 7) were reexamined in 2012-2013 (phase 11).

SETTING

The occupational cohort was originally recruited in 1985-1988.

PARTICIPANTS

A total of 3270 men and women with an average age of 60.85 years at phase 7 (2002-2004).

OUTCOME MEASURES

Incident T2D and impaired fasting glucose in 2012-2013 were measured.

RESULTS

Raised evening cortisol at phase 7 was predictive of new-onset T2D at phase 11 (odds ratio [OR], 1.18; 95% confidence interval [CI], 1.01-1.37) with a trend for a flatter slope in participants with incident T2D (odds ratio, 1.15; 95% CI, 0.99-1.33). When expanding this analysis to a broader category of glucose disturbance we found that a flattened diurnal cortisol slope at phase 7 was predictive of future impaired fasting glucose or T2D at phase 11 (OR, 1.12; 95% CI, 1.02-1.22), as was high bedtime cortisol (OR, 1.10; 95% CI, 1.01-1.20).

CONCLUSIONS

In this nonclinical population, alterations in diurnal cortisol patterns were predictive of future glucose disturbance.

Hyperglycemia in poor controlled diabetes from crude tamarind herbal pill: a case study

Hyperglycemia is an important finding in the diabetic patient with poor glycemic control. There are several possible causes of hyperglycemic. Here, the author presents an interesting case study on a female diabetic patient presenting with hyperglycemic due to intake of crude tamarind herbal pill. General practitioner should realize that the use of alternative medicine can be a cause of unexplained hyperglycemic episode in diabetic patient.

Association of diurnal patterns in salivary cortisol with type 2 diabetes in the Whitehall II study

CONTEXT

The hypothalamic pituitary-adrenal axis is thought to play a role in Type 2 Diabetes (T2D). However, the evidence for an association between diurnal cortisol patterns and T2D is equivocal.

OBJECTIVE

The aim was to examine the association of cortisol patterns throughout the day with T2D status in a community-dwelling population.

DESIGN

This was a cross-sectional study of T2D status and salivary cortisol from phase 7 (2002-2004) of the Whitehall II study, United Kingdom.

SETTING

The occupational cohort was originally recruited in 1985-1988.

PARTICIPANTS

Three-thousand, five-hundred eight white men and women including 238 participants with T2D aged 50-74 years with complete information on cortisol secretion participated.

OUTCOME MEASURES

We measured diurnal cortisol (nmol/L) patterns from six saliva samples obtained over the course of a normal day: at waking, +30 min, +2.5, +8, +12 hours, and bedtime. The cortisol awakening response and slope in diurnal secretion were calculated.

RESULTS

T2D status was associated with a flatter slope in cortisol decline across the day (b = 0.004; confidence interval [CI], 0.001-0.007; P = .014) and greater bedtime cortisol (b = 0.063; CI, 0.010-0.117; P = 0.020) independent of a wide range of covariates measured at the time of cortisol assessment. There was no association between morning cortisol, the cortisol awakening response, and T2D (P > .05).

CONCLUSIONS

In this nonclinical population, T2D was associated with a flatter slope in cortisol levels across the day and raised bedtime cortisol values.

Assessment of the degree of interference of polyphenolic compounds on glucose oxidation/peroxidase assay

The glucose oxidase/peroxidase assay (GOP) is a coupled enzymatic assay commonly used in measuring glucose concentrations in biological sciences and food chemistry, particularly for quantification of α-glucosidase activity. However, we found that the GOP assay is prone to interference, especially from reducing substances such as polyphenolic compounds, which are commonly found in botanical materials. To establish the scope and limitation of the assay in measuring α-glucosidase inhibition activity, we systematically investigated the structural features of the polyphenolic compounds that can lead to false positives. Utilizing sodium dodecyl sulfate (SDS) as surrogate for the meriquinone intermediate formed during the reaction, we measured the reactivity of this redox active intermediate toward common flavonoids. Our results show that flavonoids with o-dihydroxy groups in the B-ring cause strong interference and that compounds with little DPPH scavenging activity do not have interference. Our results highlight the need for checking the suitability of the GOP assay first before it is applied in measuring α-glucosidase inhibition activity. In addition, when the literature data on α-glucosidase inhibition activity of botanical extracts or polyphenolic compounds using GOP assay are interpreted, potential false positives due to interference on the assay will need to be taken into consideration.

Metabolically healthy obesity and the risk of cardiovascular disease and type 2 diabetes: the Whitehall II cohort study

AIM

The metabolically healthy obese (MHO) phenotype refers to obese individuals with a favourable metabolic profile. Its prognostic value is unclear and may depend on the health outcome being examined. We examined the association of MHO phenotype with incident cardiovascular disease (CVD) and type 2 diabetes.

METHODS AND RESULTS

Body mass index and metabolic health, assessed using the Adult Treatment Panel-III (ATP-III) criteria, were assessed on 7122 participants (69.7% men) from the Whitehall II study, aged 39-63 years in 1991-93. Incident CVD (coronary heart disease or stroke) and type 2 diabetes were ascertained from medical screenings (every 5 years), hospital data, and registry linkage until 2009. A total of 657 individuals (9.2% of the cohort) were obese and 42.5% of these were classified as MHO in 1991-93. Over the median follow-up of 17.4 years, there were 828 incident cases of CVD and 798 incident cases of type 2 diabetes. Compared with metabolically healthy normal weight individuals, MHO subjects were at increased risk for CVD (HR = 1.97, 95% CI: 1.38-2.80) and type 2 diabetes (3.25, 95% CI: 2.32-4.54). There was excess risk in metabolically unhealthy obese compared with MHO for type 2 diabetes (1.98, 95% CI: 1.39-2.83) but not CVD (1.23, 95% CI: 0.81-1.87). Treating all measures as time varying covariates produced similar findings.

CONCLUSION

For type 2 diabetes, the MHO phenotype is associated with lower risk than the metabolically unhealthy obese, but for CVD the risk is as elevated in both obesity phenotypes.

Metabolically healthy obesity and risk of mortality: does the definition of metabolic health matter?

OBJECTIVE

To assess the association of a "metabolically healthy obese" phenotype with mortality using five definitions of metabolic health.

RESEARCH DESIGN AND METHODS

Adults (n = 5,269; 71.7% men) aged 39-62 years in 1991 through 1993 provided data on BMI and metabolic health, defined using data from the Adult Treatment Panel-III (ATP-III); criteria from two studies; and the Matsuda and homeostasis model assessment (HOMA) indices. Cross-classification of BMI categories and metabolic status (healthy/unhealthy) created six groups. Cox proportional hazards regression models were used to analyze associations with all-cause and cardiovascular disease (CVD) mortality during a median follow-up of 17.7 years.

RESULTS

A total of 638 individuals (12.1% of the cohort) were obese, of whom 9-41% were metabolically healthy, depending on the definition. Regardless of the definition, compared with metabolically healthy, normal-weight individuals, both the metabolically healthy obese (hazard ratios [HRs] ranged from 1.81 [95% CI 1.16-2.84] for ATP-III to 2.30 [1.13-4.70] for the Matsuda index) and the metabolically abnormal obese (HRs ranged from 1.57 [1.08-2.28] for the Matsuda index to 2.05 [1.44-2.92] for criteria defined in a separate study) had an increased risk of mortality. The only exception was the lack of excess risk using the HOMA criterion for the metabolically healthy obese (1.08; 0.67-1.74). Among the obese, the risk of mortality did not vary as a function of metabolic health apart from when using the HOMA criterion (1.93; 1.15-3.22). Similar results were obtained for cardiovascular mortality.

CONCLUSIONS

For most definitions of metabolic health, both metabolically healthy and unhealthy obese patients carry an elevated risk of mortality.

Obesity phenotypes in midlife and cognition in early old age: the Whitehall II cohort study

OBJECTIVE

To examine the association of body mass index (BMI) and metabolic status with cognitive function and decline.

METHODS

A total of 6,401 adults (71.2% men), aged 39-63 years in 1991-1993, provided data on BMI (normal weight 18.5-24.9 kg/m(2), overweight 25-29.9 kg/m(2); and obese ≥30 kg/m(2)) and metabolic status (abnormality defined as 2 or more of 1) triglycerides ≥1.69 mmol/L or lipid-lowering drugs, 2) systolic blood pressure ≥130 mm Hg, diastolic blood pressure ≥85 mm Hg, or antihypertensive drugs, 3) glucose ≥5.6 mmol/L or medications for diabetes, and 4) high-density lipoprotein cholesterol <1.04 mmol/L for men and <1.29 mmol/L for women). Four cognitive tests (memory, reasoning, semantic, and phonemic fluency) were administered in 1997-1999, 2002-2004, and 2007-2009, standardized to z scores, and averaged to yield a global score.

RESULTS

Of the participants, 31.0% had metabolic abnormalities, 52.7% were normal weight, 38.2% were overweight, and 9.1% were obese. Among the obese, the global cognitive score at baseline (p = 0.82) and decline (p = 0.19) over 10 years was similar in the metabolically normal and abnormal groups. In the metabolically normal group, the 10-year decline in the global cognitive score was similar (p for trend = 0.36) in the normal weight (-0.40; 95% confidence interval [CI] -0.42 to -0.38), overweight (-0.42; 95% CI -0.45 to -0.39), and obese (-0.42; 95% CI -0.50 to -0.34) groups. However, in the metabolically abnormal group, the decline on the global score was faster among obese (-0.49; 95% CI -0.55 to -0.42) than among normal weight individuals (-0.42; 95% CI -0.50 to -0.34), (p = 0.03).

CONCLUSIONS

In these analyses the fastest cognitive decline was observed in those with both obesity and metabolic abnormality.

Work stress, obesity and the risk of type 2 diabetes: gender-specific bidirectional effect in the Whitehall II study

Psychosocial work stress has been linked to higher risk of type 2 diabetes (T2DM), with the effect being consistently higher among women than men. Also, work stress has been linked to prospective weight gain among obese men but weight loss among lean men. Here, we aimed to examine the interaction between work stress and obesity in relation to T2DM risk in a gender-specific manner. We studied 5,568 white middle-aged men and women in the Whitehall II study, who were free from diabetes at analysis baseline (1993). After 1993, diabetes was ascertained at six consecutive phases by an oral glucose tolerance test supplemented by self-reports. Cox regression analysis was used to assess the association between job strain (high job demands/low job control) and 18-year incident T2DM stratifying by BMI (BMI <30 kg/m(2) vs. BMI ≥30 kg/m(2)). Overall, work stress was associated with incident T2DM among women (hazard ratio (HR) 1.41: 95% confidence intervals: 1.02; 1.95) but not among men (HR 0.87: 95% confidence interval 0.69; 1.11) (P(INTERACTION) = 0.017). Among men, work stress was associated with a lower risk of T2DM in nonobese (HR 0.70: 0.53; 0.93) but not in obese individuals (P(INTERACTION) = 0.17). Among women, work stress was associated with higher risk of T2DM in the obese (HR 2.01: 1.06; 3.92) but not in the nonobese (P(INTERACTION) = 0.005). Gender and body weight status play a critical role in determining the direction of the association between psychosocial stress and T2DM. The potential effect-modifying role of gender and obesity should not be ignored by future studies looking at stress-disease associations.

Pregnancy-specific protein B (PSPB), progesterone and some biochemical attributes concentrations in the fetal fluids and serum and its relationship with fetal and placental characteristics of Iraqi riverine buffalo (Bubalus bubalis)

This study was carried out to demonstrate the pregnancy-specific protein B (PSPB), progesterone and some biochemical parameters concentrations in amniotic fluid, allantoic fluid and fetal serum collected from slaughtered Iraqi riverine pregnant buffaloes at three different months of gestation (6th, 7th and 8th). Ten out of 22 adult buffaloes of 4.6 ± 0.97 years old were used in this study. The buffaloes were mated naturally by monitoring the estrus cycles via appearance of vaginal fluids and mounting by bulls. Pregnancy was checked for these buffaloes by non-returning to estrus for three estrus cycles and assured by rectal palpation on day 61 post-mating (PM). Buffaloes were slaughtered at three different periods of gestation (three at 6th month, four at 7th month and three at 8th month of gestation) to verify the progesterone and PSPB as well as some blood attributes levels (glucose, cholesterol, total protein, albumin, globulins and albumin: globulins ratio) in amniotic fluid (AF), allantoic fluid (LF) and fetal serum (FS). Progesterone was higher (P<0.01) in LF at the 8th month of gestation and lower in FS during the 7th and 8th months of pregnancy. PSPB concentrations were greater in FS (6th and 8th months in particular) than in both AF and LF. The overall mean of cholesterol concentration was higher in FS (P<0.05) followed by AF and LF that had the lowest concentration. The FS exhibited higher total protein during the three gestation periods. Most of fetal and placental measurements increased as the pregnancy advanced. In conclusion, these results described, for the first time, the PSPB and progesterone concentrations and blood characteristics in fetal fluids and serum in water riverine buffaloes during different stages of pregnancy. Progesterone concentrations were greater in allantoic fluid than in other fluids. In contrast, PSPB and other blood attributes were higher in fetal serum than other fluids of Iraqi riverine buffaloes. These findings reflect the changes in hormones, proteins and other metabolites during different gestation periods.

Antidepressant medication use and risk of hyperglycemia and diabetes mellitus: a noncausal association?

BACKGROUND

Previous research suggests a link between antidepressant use and diabetes, but it is unclear whether the association is causal or attributable to detection/ascertainment bias. To examine this, we assessed the associations of antidepressant use with change in glucose levels and incidence of undiagnosed and diagnosed diabetes.

METHODS

During an 18-year period, we monitored antidepressant use, glucose levels, and diabetes status in 5978 civil servants (70.9% male, age range 39-64 years) free of diabetes at baseline (the Whitehall II study). Use of medication and plasma glucose were assessed at four study screenings: 1991/1993, 1997/1999, 2003/2004, and 2008/2009. Incident diabetes cases were classified as either diagnosed (n = 294) if detected using self-report of physician diagnosis and/or the use of diabetes medication or undiagnosed (n = 346) if detected based on fasting and/or 2-hour postload glucose levels using an oral glucose tolerance test at the study screenings.

RESULTS

Incidence of diagnosed diabetes was higher among antidepressant users than nonusers (odds ratio 3.10, 95% confidence interval: 1.66-5.78). However, antidepressant use was not associated with undiagnosed diabetes at any follow-up examination nor with higher fasting or 2-hour postload plasma glucose levels or increasing glucose levels over time. Odds ratio for undiagnosed diabetes for antidepressant users versus nonusers was .88 (95% confidence interval: .45-1.72, p = .70). The mean difference in glucose changes between participants reporting antidepressant use at three screenings compared with those not on antidepressant treatment was .0 mmol/L.

CONCLUSIONS

The link between antidepressant use and diabetes risk may not be causal in nature.

Relation between glucose levels, high-sensitivity C-reactive protein (hs-CRP), body mass index (BMI) and serum and dietary retinol in elderly in population-based study

The aim of this study was to evaluate the relationships between fasting glucose levels, hs-CRP, BMI and serum retinol and diet in elderly people. For this study, a cross-sectional, epidemiological, population-based format was adopted. One hundred and sixty-three individuals between 60 and 90 years of age participated; the participants were from different socioeconomic and health backgrounds, except for the individuals diagnosed with diabetes. Most subjects had serum concentrations in the reference ranges for all variables. There was not a significant relationship between fasting glucose and serum retinol or diet. There was a significant correlation between hs-CRP and BMI (r=0.22, p=0.0082) and hs-CRP and total calorie intake (p=0.0091), which reinforces the notion that an increased intake of calories results in being overweight and/or obese. Considering the importance of vitamin A in various physiological processes, more studies on these relationships are necessary to establish a recommendation of vitamin A for the treatment and prevention of changes in fasting glucose and obesity in the elderly population.

Association of diurnal patterns in salivary cortisol with all-cause and cardiovascular mortality: findings from the Whitehall II study

CONTEXT

Evidence for the association of cortisol with mortality or disease events is mixed, possibly due to a failure to consider diurnal cortisol patterns.

OBJECTIVE

Our objective was to examine the association of diurnal cortisol patterns throughout the day with cardiovascular and noncardiovascular mortality in a community-dwelling population.

DESIGN

This was a prospective cohort study among 4047 civil servants, the Whitehall II study, United Kingdom. We measured diurnal cortisol patterns in 2002-2004 from six saliva samples obtained over the course of a normal weekday: at waking, +30 min, +2.5 h, +8 h, +12 h, and bedtime. Participants were subsequently followed for all-cause and cause-specific mortality until January 2010.

PARTICIPANTS

Participants included 4047 men and women aged 61 yr on average at baseline.

OUTCOMES

We assessed all-cause, cardiovascular, and noncardiovascular death.

RESULTS

There were 139 deaths, 32 of which were deaths due to cardiovascular disease, during a mean follow-up period of 6.1 yr. Flatter slopes in cortisol decline across the day were associated with increased risk of all-cause mortality (hazard ratio for 1 sd reduction in slope steepness 1.30; 95% confidence interval (CI) = 1.09-1.55). This excess mortality risk was mainly driven by an increased risk of cardiovascular deaths (hazard ratio = 1.87; 95% confidence interval = 1.32-2.64). The association with cardiovascular deaths was independent of a wide range of covariates measured at the time of cortisol assessment. There was no association between morning cortisol, the cortisol awakening response, and mortality outcomes.

CONCLUSIONS

These findings demonstrate, for the first time, the relationship between a flatter slope in cortisol levels across the day and an increased risk of cardiovascular disease mortality in a nonclinical population.

Associations of common genetic variants with age-related changes in fasting and postload glucose: evidence from 18 years of follow-up of the Whitehall II cohort

OBJECTIVE

In the general, nondiabetic population, fasting glucose increases only slightly over time, whereas 2-h postload glucose shows a much steeper age-related rise. The reasons underlying these different age trajectories are unknown. We investigated whether common genetic variants associated with fasting and 2-h glucose contribute to age-related changes of these traits.

RESEARCH DESIGN AND METHODS

We studied 5,196 nondiabetic participants of the Whitehall II cohort (aged 40-78 years) attending up to four 5-yearly oral glucose tolerance tests. A genetic score was calculated separately for fasting and 2-h glucose, including 16 and 5 single nucleotide polymorphisms, respectively. Longitudinal modeling with age centered at 55 years was used to study the effects of each genotype and genetic score on fasting and 2-h glucose and their interactions with age, adjusting for sex and time-varying BMI.

RESULTS

The fasting glucose genetic score was significantly associated with fasting glucose with a 0.029 mmol/L (95% CI 0.023-0.034) difference (P = 2.76 × 10(-21)) per genetic score point, an association that remained constant over time (age interaction P = 0.17). Two-hour glucose levels differed by 0.076 mmol/L (0.047-0.105) per genetic score point (P = 3.1 × 10(-7)); notably, this effect became stronger with increasing age by 0.006 mmol/L (0.003-0.009) per genetic score point per year (age interaction P = 3.0 × 10(-5)), resulting in diverging age trajectories by genetic score.

CONCLUSIONS

Common genetic variants contribute to the age-related rise of 2-h glucose levels, whereas associations of variants for fasting glucose are constant over time, in line with stable age trajectories of fasting glucose.

Utility of genetic and non-genetic risk factors in prediction of type 2 diabetes: Whitehall II prospective cohort study

OBJECTIVES

To assess the performance of a panel of common single nucleotide polymorphisms (genotypes) associated with type 2 diabetes in distinguishing incident cases of future type 2 diabetes (discrimination), and to examine the effect of adding genetic information to previously validated non-genetic (phenotype based) models developed to estimate the absolute risk of type 2 diabetes.

DESIGN

Workplace based prospective cohort study with three 5 yearly medical screenings.

PARTICIPANTS

5535 initially healthy people (mean age 49 years; 33% women), of whom 302 developed new onset type 2 diabetes over 10 years.

OUTCOME MEASURES

Non-genetic variables included in two established risk models-the Cambridge type 2 diabetes risk score (age, sex, drug treatment, family history of type 2 diabetes, body mass index, smoking status) and the Framingham offspring study type 2 diabetes risk score (age, sex, parental history of type 2 diabetes, body mass index, high density lipoprotein cholesterol, triglycerides, fasting glucose)-and 20 single nucleotide polymorphisms associated with susceptibility to type 2 diabetes. Cases of incident type 2 diabetes were defined on the basis of a standard oral glucose tolerance test, self report of a doctor's diagnosis, or the use of anti-diabetic drugs.

RESULTS

A genetic score based on the number of risk alleles carried (range 0-40; area under receiver operating characteristics curve 0.54, 95% confidence interval 0.50 to 0.58) and a genetic risk function in which carriage of risk alleles was weighted according to the summary odds ratios of their effect from meta-analyses of genetic studies (area under receiver operating characteristics curve 0.55, 0.51 to 0.59) did not effectively discriminate cases of diabetes. The Cambridge risk score (area under curve 0.72, 0.69 to 0.76) and the Framingham offspring risk score (area under curve 0.78, 0.75 to 0.82) led to better discrimination of cases than did genotype based tests. Adding genetic information to phenotype based risk models did not improve discrimination and provided only a small improvement in model calibration and a modest net reclassification improvement of about 5% when added to the Cambridge risk score but not when added to the Framingham offspring risk score.

CONCLUSION

The phenotype based risk models provided greater discrimination for type 2 diabetes than did models based on 20 common independently inherited diabetes risk alleles. The addition of genotypes to phenotype based risk models produced only minimal improvement in accuracy of risk estimation assessed by recalibration and, at best, a minor net reclassification improvement. The major translational application of the currently known common, small effect genetic variants influencing susceptibility to type 2 diabetes is likely to come from the insight they provide on causes of disease and potential therapeutic targets.

Hyperglycemia, type 2 diabetes, and depressive symptoms: the British Whitehall II study

OBJECTIVE

To examine the recent suggestion that impaired fasting glucose may protect against depression, whereas a diagnosis of diabetes might then result in depression.

RESEARCH DESIGN AND METHODS

Cross-sectional analysis of 4,228 adults (mean age 60.7 years, 73.0% men) who underwent oral glucose tolerance testing and completed the Center for Epidemiologic Studies Depression scale (CES-D).

RESULTS

After adjustment for demographic factors, health behaviors, and clinical measurements (BMI, waist circumference, lipid profile, and blood pressure), there was a U-shaped association between fasting glucose and depression (P(curve) = 0.001), with elevated CES-D at low and very high glucose levels. This finding was replicable with 2-h postload glucose (P = 0.11) and A1C (P = 0.007).

CONCLUSIONS

The U-shaped association between blood glucose and CES-D, with the lowest depression risk seen among those in the normoglycemic range of A1C, did not support the hypothesized protective effect of hyperglycemia.

Trajectories of glycaemia, insulin sensitivity, and insulin secretion before diagnosis of type 2 diabetes: an analysis from the Whitehall II study

BACKGROUND

Little is known about the timing of changes in glucose metabolism before occurrence of type 2 diabetes. We aimed to characterise trajectories of fasting and postload glucose, insulin sensitivity, and insulin secretion in individuals who develop type 2 diabetes.

METHODS

We analysed data from our prospective occupational cohort study (Whitehall II study) of 6538 (71% male and 91% white) British civil servants without diabetes mellitus at baseline. During a median follow-up period of 9.7 years, 505 diabetes cases were diagnosed (49.1% on the basis of oral glucose tolerance test). We assessed retrospective trajectories of fasting and 2-h postload glucose, homoeostasis model assessment (HOMA) insulin sensitivity, and HOMA beta-cell function from up to 13 years before diabetes diagnosis (diabetic group) or at the end of follow-up (non-diabetics).

FINDINGS

Multilevel models adjusted for age, sex, and ethnic origin confirmed that all metabolic measures followed linear trends in the group of non-diabetics (10,989 measurements), except for insulin secretion that did not change during follow-up. In the diabetic group (801 measurements), a linear increase in fasting glucose was followed by a steep quadratic increase (from 5.79 mmol/L to 7.40 mmol/L) starting 3 years before diagnosis of diabetes. 2-h postload glucose showed a rapid increase starting 3 years before diagnosis (from 7.60 mmol/L to 11.90 mmol/L), and HOMA insulin sensitivity decreased steeply during the 5 years before diagnosis (to 86.7%). HOMA beta-cell function increased between years 4 and 3 before diagnosis (from 85.0% to 92.6%) and then decreased until diagnosis (to 62.4%).

INTERPRETATION

In this study, we show changes in glucose concentrations, insulin sensitivity, and insulin secretion as much as 3-6 years before diagnosis of diabetes. The description of biomarker trajectories leading to diabetes diagnosis could contribute to more-accurate risk prediction models that use repeated measures available for patients through regular check-ups.

FUNDING

Medical Research Council (UK); Economic and Social Research Council (UK); British Heart Foundation (UK); Health and Safety Executive (UK); Department of Health (UK); National Institute of Health (USA); Agency for Health Care Policy Research (USA); the John D and Catherine T MacArthur Foundation (USA); and Academy of Finland (Finland).

Comparison between 100-g glucose tolerance test and two other screening tests for gestational diabetes: combined fasting glucose with risk factors and 50-g glucose tolerance test

CONTEXT AND OBJECTIVE

Lack of consensus about which screening tests to use for gestational diabetes mellitus (GDM) and difficulties in performing the gold-standard diagnostic test, the 100-g glucose tolerance test (100-g GTT), justify comparison with alternatives. The aim was to compare this with two other screening tests: combined fasting glucose with risk factors (FG + RF) and 50-g GTT.

DESIGN AND SETTING

Prospective longitudinal cohort study in the Hospital School of Universidade Federal de Mato Grosso do Sul.

METHODS

The three tests were performed independently on 341 pregnant women. Sensitivity (S), specificity (Sp), positive (PPV) and negative (NPV) predictive values, positive (PLR) and negative (NLR) likelihood ratios, and false-positive (FP) and false-negative (FR) rates obtained with FG + RF and 50-g GTT were compared with values from 100-g GTT. The average one-hour post-intake glucose levels (1hPG) with 50-g and 100-g were compared. Students t test was used in the statistical analysis.

RESULTS

FG + RF led more pregnant women (53.9%) to diagnostic confirmation than did 50-g GTT (14.4%). The tests were equivalent for S (86.4 and 76.9%), PPV (98.7 and 98.9%), NLR (0.3 and 0.27) and FR (15.4 and 23.1%). Average 1hPG values were similar: 50-g GTT = 106.8 mg/dl and 100-g GTT = 107.5 mg/dl.

CONCLUSION

Diagnostic efficiency with simplicity, practicality and low cost make FG + RF more appropriate for screening for GDM. The equivalence of 1hPG allows a new, cheaper and less uncomfortable protocol to be proposed for screening and diagnosing GDM.

Joint distribution of non-HDL and LDL cholesterol and coronary heart disease risk prediction among individuals with and without diabetes

OBJECTIVE

To assess coronary heart disease (CHD) risk within levels of the joint distribution of non-HDL and LDL cholesterol among individuals with and without diabetes.

RESEARCH DESIGN AND METHODS

We used four publicly available data sets for this pooled post hoc analysis and confined the eligible subjects to white individuals aged > or = 30 years and free of CHD at baseline (12,660 men and 6,721 women). Diabetes status was defined as either "reported by physician-diagnosed and on medication" or having a fasting glucose level > or = 126 mg/dl at the baseline examination. The primary end point was CHD death. Within diabetes categories, risk was assessed based on lipid levels (in mg/dl): non-HDL <130 and LDL <100 (group 1); non-HDL <130 and LDL > or = 100 (group 2); non-HDL > or = 130 and LDL <100 (group 3); and non-HDL > or = 130 and LDL > or = 100 (group 4). Group 1 within those without diabetes was the overall reference group.

RESULTS

Of the subjects studied, approximately 6% of men and 4% of women were defined as having diabetes. A total of 773 CHD deaths occurred during the average 13 years of follow-up time. A Cox proportional hazard model was used to estimate the relative risk (RR) of CHD death. Those with diabetes had a 200% higher RR than those without diabetes. In a multivariate model, CHD risk in those with diabetes did not increase with increasing LDL, whereas it did increase with increasing non-HDL: RR (95% confidence interval) for group 1: 5.7 (2.0-16.8); group 2: 5.7 (1.6-20.7); group 3: 7.2 (2.6-19.8); and group 4: 7.1 (3.7-13.6).

CONCLUSIONS

Non-HDL is a stronger predictor of CHD death among those with diabetes than LDL and should be given more consideration in the clinical approach to risk reduction among diabetic patients.

Performance evaluation of the Precision PCx point-of-care blood glucose analyzer using discriminant ratio methodology

Point-of-care glucose testing needs to be integrated into a laboratory information system to provide continuous care. Selecting a particular glucose monitoring system is based on both analytical performance and on user's preference. We evaluated accuracy, performance and regulatory compliance of the Precision PCx glucose analyzer (Abbott), with automatic download into a central station, for remote quality control (QC) management and automatic upgrading. We used the discriminant ratio (DR) methodology, which determines the DR of a test (e.g. the ratio between the underlying SD and the within-subject SD), and compares it to that of another test allegedly measuring the same parameter. Accuracy was evaluated by Clarke's error grid method. Seven hundred and ninety four blood samples were taken from 22 diabetic patients, combined with two capillary blood samples: one for analysis by reference method and the second for PCx analysis. Linear regression analysis revealed, over a 2.1 to 26.9 mmol/l glucose concentration range, a correlation coefficient of 0.963, an intercept of 0.7 mmol/l and a slope of 0.851. Mean difference between meter-generated results and the reference method was -7.1+/-10.8%. Between-run imprecision for PCx using Abbott's controls at low and mid-low concentrations was 5.4 and 3.8%, respectively. Clarke's error grid did not show any clinical impact related to difference between methods. DRs were of similar magnitude using both methods. Nursing staff found PCx easy for everyday use. Our data show that PCx results agree with those obtained with the reference method, as shown by lack of significant difference in DRs, and by excellent correlation.

Spatial distribution of nociceptive neuropeptide and nerve growth factor depletion in experimental diabetic peripheral nervous system

This study investigated the time-course of the nociceptive neuropeptide substance P and nerve growth factor (NGF), which facilitates substance P production, in lumbar and cervical dorsal root ganglia (DRG) of streptozotocin-induced diabetic rats. Levels of substance P and NGF were measured by radioimmunoassay and sandwich enzyme-linked immunosorbent assay, respectively, 2 months, 4 months and 8 months after induction of diabetes, and compared with age-matched non-diabetic control rats. At 2 months and 4 months, substance P and NGF levels were lower in the lumbar DRG of the diabetic rats than in controls. At 8 months, substance P and NGF were lower in both the lumbar and cervical DRG of the diabetic rats than in controls. These data demonstrate that a decrease in substance P levels in primary sensory neurons with NGF depletion occurs in an axonal length-dependent manner in diabetic rats, and that this decrease may be correlated with the duration of diabetes.

Recent advances in amperometric glucose biosensors for in vivo monitoring

Electrochemical biosensors for glucose, based on the specific glucose oxidizing enzyme glucose oxidase, have generated considerable interest. Several commercial devices based on this principle have been developed and are widely used for in vitro monitoring of glucose e.g. in hospitals, doctors surgeries and for home monitoring by patients themselves. A significant advance in the application of biosensor technology would be the development of portable, implantable sensors which could continuously indicate the blood glucose concentration, enabling swift corrective action to be taken by the patient. This review highlights recent developments in amperometric glucose biosensors for in vivo monitoring and also considers the remaining barrier which need to be overcome to enable successful introduction of an implantable sensor.

Response of lipoprotein lipase to calorie intake in streptozotocin-induced diabetic rats

The mechanism regulating lipoprotein lipase (LPL) expression in adipose tissue was examined in rats in the conditions of different calorie intakes with and without streptozotocin-induced (STZ-) diabetes. The LPL activity released from adipose tissue was greater with the higher calorie intake (20 g of normal chow diet per day) than with the lower calorie intake (13 g of normal chow diet per day), and was greater in normal rats than in STZ-diabetic rats. The LPL activity was proportional to the serum insulin level in all conditions. Dot-blot analysis showed that the amount of LPL mRNA in adipose tissue was increased by the higher calorie diet and that the increase was less in the diabetic state. Expression of mRNA was also nearly parallel with the serum insulin level. LPL activity released from the heart was not affected by either the calorie intake or the diabetic state. These results suggest that the mechanisms of LPL expression in adipose tissue and the heart are different, and that LPL expression in adipose tissue was closely dependent on the insulin level.

An investigation into the effects of aminoguanidine treatment on the plasma and blood of free-fed and dietary-restricted rats

An investigation has been made into the effect of oral aminoguanidine (50-60 mg kg-1 day-1) on the blood biochemistry of male Wistar rats which either had free access to food or were dietary-restricted (50% of the food consumed by the free access group). In control rats (i.e. without aminoguanidine treatment) three weeks of food restriction caused significant increases in plasma sodium and albumin and the erythrocyte count, haematocrit and haemoglobin. There were reductions in plasma calcium, phosphate, alkaline phosphatase activity, urea, triglycerides, creatinine, glucose and the red cell volume. Similar effects of food restriction were observed in aminoguanidine-treated rats. Aminoguanidine ingestion in free-fed animals caused a reduction in plasma creatinine concentration. In dietary-restricted rats, aminoguanidine ingestion reduced plasma sodium and total plasma proteins (largely as a result of a decline in albumin), and increased plasma urea concentrations. Aminoguanidine was added to plasma of control rats in-vitro to determine whether it interfered with the assay of urea and creatinine. At concentrations of 0.1 to 10 mg mL-1, aminoguanidine had no effect on urea determinations. However, aminoguanidine significantly reduced the apparent concentration of plasma creatinine by between 7 to 81%. The changes in plasma analytes in aminoguanidine-treated rats may be indicative of minor hepatic perturbations or kidney function, but the data also imply that prior nutritional state is a determinant of aminoguanidine effects.

Measurement of protein synthesis by the phenylalanine flooding dose technique: effect of phenylalanine and anaesthesia on plasma electrolyte, enzyme and metabolite levels

Ten minutes after an intravenous flooding dose of phenylalanine to rats, plasma sodium and calcium concentrations were slightly reduced (by 2-7%) but no effects on potassium or phosphate were observed. Creatine kinase activities were significantly increased by phenylalanine injection (by 39%), but alkaline phosphatase, alanine aminotransferase, lactate dehydrogenase and aspartate aminotransferase activities were unaltered. Plasma concentrations of total proteins, albumin, cholesterol, triglycerides, urea, creatinine and glucose were also unaffected. In the presence of anaesthesia, phenylalanine injection had almost identical effects, although the increase in creatine kinase activities did not reach statistical significance. Anaesthesia for 10 min reduced plasma potassium concentrations (by 27%), and calcium (by 5%), though phosphate and sodium were unaltered. The activities of lactate dehydrogenase, creatine kinase and aspartate aminotransferase were reduced by between 36-52%, but alkaline phosphatase and alanine aminotransferase activities were unaltered by anaesthesia. Plasma concentrations of total proteins and albumin were also reduced (both by 9%), but glucose concentrations were increased (by 33%). Anaesthesia had no other significant effects on cholesterol, triglycerides, urea or creatinine concentrations. The qualitative effects of anaesthesia in the presence of raised free phenylalanine concentrations were similar. It was concluded that, except for creatine kinase, determinations of plasma constituents in phenylalanine-injected rats could be made without overt interpretational errors. However, caution is required in interpreting data on plasma constituents from anaesthetized rats.

Chemical Sensing in Process Analysis

Improvements in process control, which determine production efficiency and product quality, are critically dependent upon on-line process analysis. The technology of the required instrumentation will be substantially expanded by advances in sensing devices. In the future, the hardware will consist of sensor arrays and miniaturized instruments fabricated by microlithography and silicon micromachining. Chemometrics will be extensively used in software to provide error detection, selfcalibration, and correction as well as multivariate data analysis for the determination of anticipated and unanticipated species. A number of examples of monolithically fabricated sensors now exist and more will be forthcoming as the new paradigms and new tools are widely adopted. A trend toward not only on-line but even in-product sensors is becoming discernible.

Interrelationships of microangiopathy, plasma glucose and other risk factors in 3583 diabetic patients: a multinational study

In a multinational study, fasting plasma glucose values in 3583 diabetic patients, aged 34-56 years, were related to the characteristics of these subjects and to the presence and severity of microangiopathy as ascertained by standardised methods. The patients were from nine different populations and ranged in number from 193 to 686 per population (London, Warsaw, Berlin (FRG), New Delhi, Tokyo, Havana, Oklahoma Indians, Arizona Pima Indians, and a national sample in Switzerland). In the total group, mean fasting plasma glucose was 8.1 mmol/l for those on diet alone, 9.7 mmol/l for those on oral agents, and 12.7 mmol/l for insulin-treated patients, of whom 25% had values exceeding 16.5 mmol/l. Since many variables were measured in each patient, it was possible to take into account many confounding factors in evaluating the relationship of plasma glucose levels to retinopathy and nephropathy.

T-lymphocytes transfer streptozotocin induced diabetes mellitus in mice

Diabetes mellitus induced by low dose treatment with streptozotocin in BALB/c mice was passively transferred to syngeneic recipients with a predominantly T-lymphocyte fraction of spleen cells. This fraction was prepared by density centrifugation and passage through an antimouse immunoglobulin coated column. Variation in numbers of injected cells in the range of 10(3) to 10(7) showed that the smaller cell numbers gave the highest blood sugar values. Athymic nude recipients of BALB/c background also developed diabetes following similar transplants. A preliminary result was that the highest blood sugars were seen after transplantation of T-lymphocytes treated by low dose irradiation (200 R). This may reflect a specific effect on T-suppressor lymphocytes.