Failure of hyperglycemia and hyperinsulinemia to compensate for impaired metabolic response to an oral glucose load.

OBJECTIVE: To evaluate whether the augmented insulin and glucose response to a glucose challenge is sufficient to compensate for defects in glucose utilization in obesity and type 2 diabetes, using a breath test measurement of integrated glucose metabolism. METHODS: Non-obese, obese normoglycemic and obese type 2 diabetic subjects were studied on 2 consecutive days. A 75g oral glucose load spiked with ¹³C-glucose was administered, measuring exhaled breath ¹³CO2 as an integrated measure of glucose metabolism and oxidation. A hyperinsulinemic euglycemic clamp was performed, measuring whole body glucose disposal rate. Body composition was measured by DEXA. Multivariable analyses were performed to evaluate the determinants of the breath ¹³CO2. RESULTS: Breath ¹³CO2 was reduced in obese and type 2 diabetic subjects despite hyperglycemia and hyperinsulinemia. The primary determinants of breath response were lean mass, fat mass, fasting FFA concentrations, and OGTT glucose excursion. Multiple approaches to analysis showed that hyperglycemia and hyperinsulinemia were not sufficient to compensate for the defect in glucose metabolism in obesity and diabetes. CONCLUSIONS: Augmented insulin and glucose responses during an OGTT are not sufficient to overcome the underlying defects in glucose metabolism in obesity and diabetes.

Vaginismus and its correlates in an Iranian clinical sample.

Although vaginismus is a relatively common female sexual dysfunction in Iran, there are scant studies reporting on its clinical and social features. The aim of the present study was to compare the social and clinical characteristics of women with vaginismus with those of healthy women. The study comprises 22 patients with vaginismus and 22 healthy controls who presented to the health clinics of Tehran University of Medical Sciences, Iran. We used three assessment tools: interview, a (34-item) questionnaire for demographic and clinical characteristics of vaginismus and a 13-item questionnaire of Female Sexual Distress Scale-Revised (FSDS-R) for sexual distress. The majority (73%) of women with vaginismus had primary vaginismus (unconsummated marriage). These women demonstrated significant higher phobia than healthy women, including fear of genital pain and penetration, fear of bleeding during intercourse, height phobia, aversion to looking or touching the genitalia, fear of vaginal disproportion and also disgust of semen. Compared with the healthy women, these women displayed a significantly higher sexual distress score, defecation or urination problems, general anxiety, higher education levels and lower self-esteem. Our findings suggest that there is a strong correlation between vaginismus, phobia and anxiety.

Isotopic decay of urinary or plasma 3-methylhistidine as a potential biomarker of pathologic skeletal muscle loss.

BACKGROUND: Skeletal muscle loss accompanying aging or cancer is associated with reduced physical function and predicts morbidity and mortality. 3-Methylhistidine (3MH) has been proposed as a biomarker of myofibrillar proteolysis, which may contribute to skeletal muscle loss. METHODS: We hypothesized that the terminal portion of the isotope decay curve following an oral dose of isotopically labeled 3MH can be measured non-invasively from timed spot urine samples. We investigated the feasibility of this approach by determining isotope enrichment in spot urine samples and corresponding plasma samples and whether meat intake up to the time of dosing influences the isotope decay. RESULTS: Isotope decay constants (k) were similar in plasma and urine, regardless of diet. Post hoc comparison of hourly sampling over 10 h with three samples distributed over 10 or fewer hours suggests that three distributed samples over 5-6 h of plasma or urine sampling yield decay constants similar to those obtained over 10 h of hourly sampling. CONCLUSION: The findings from this study suggest that an index of 3MH production can be obtained from an easily administered test involving oral administration of a stable isotope tracer of 3MH followed by three plasma or urine samples collected over 5-6 h the next day.

Hip circumference, height and risk of type 2 diabetes: systematic review and meta-analysis.

Although several epidemiological studies have investigated the relationship between type 2 diabetes mellitus (T2DM) and hip circumference or height, the results are inconsistent. The present systematic review and meta-analysis of published observational studies was conducted to assess the effects of hip circumference and height on diabetes risk. Online databases were searched through January 2012, and the reference lists of pertinent articles reporting observational studies in humans were examined. Pooled relative risks (RR) and 95% confidence intervals (CI) were calculated with a random-effects model. Eighteen studies (nine cross-sectional and nine cohort) were included, with 250,497 participants and 7,765 cases of T2DM. Hip circumference was inversely associated with an increased risk of T2DM in men (summary RR [95% CI] 0.60 [0.45, 0.80]) and women (0.54 [0.42, 0.70]). These results were consistent between cross-sectional and cohort studies. An inverse association between height and T2DM was observed in women only (summary RR [95% CI] 0.83 [0.73, 0.95]). Our meta-analysis strongly supports an inverse relationship between hip circumference and risk of T2DM in men and women. The inverse association between height and risk was significant only in women.

Effect of dairy consumption on weight and body composition in adults: a systematic review and meta-analysis of randomized controlled clinical trials.

BACKGROUND: Although several observational and experimental studies have investigated the effect of dairy consumption on weight and body composition, results are inconsistent. OBJECTIVE: This systematic review and meta-analysis was conducted to summarize the published evidence from randomized controlled clinical trials (RCTs) regarding the effect of dairy consumption on weight, body fat mass, lean mass and waist circumference (WC) in adults. DESIGN: PubMed, ISI Web of Science, SCOPUS, Science Direct and EMBASE were searched from January 1960 to October 2011 for relevant English and non-English publications. Sixteen studies were selected for the systematic review and fourteen studies were included in meta-analysis. RESULTS: Our search led to 14, 12, 6 and 8 eligible RCTs that had data on weight, body fat mass, lean mass and WC, respectively. Overall, mean difference for the effect of dairy on body weight was -0.61 kg (95% confidence interval (CI): -1.29, 0.07, P=0.08). Increased dairy intake resulted in 0.72 kg (95% CI: -1.29, -0.14, P=0.01) greater reduction in fat mass, 0.58 kg (95% CI: 0.18, 0.99, P<0.01) gain in lean mass and 2.19 cm (95% CI: -3.42, -0.96, P-value <0.001) further reduction in WC than that in controls. Subgroup analysis revealed that increasing dairy intake without energy restriction in both intervention and control groups does not significantly affect weight, body fat mass, lean mass and WC; consumption of high-dairy weight loss diets led to 1.29 kg (95% CI: -1.98, -0.6, P<0.001) greater weight loss, 1.11 kg (95% CI: -1.75, -0.47, P=0.001) greater reduction in body fat mass, 0.72 kg (95% CI: 0.12, 1.32, P=0.02) gain in body lean mass and 2.43 cm (95% CI: -3.42, -1.44, P<0.001) additional reduction in WC compared with controls. CONCLUSION: Increased dairy consumption without energy restriction might not lead to a significant change in weight or body composition; whereas inclusion of dairy products in energy-restricted weight loss diets significantly affects weight, body fat mass, lean mass and WC compared with that in the usual weight loss diets.

Effect of rs6983267 polymorphism in the 8q24 region and rs4444903 polymorphism in EGF gene on the risk of sporadic colorectal cancer in Iranian population.

Colorectal cancer (CRC) is among the major causes of cancer-related morbidity, mortality, and human health problem worldwide. Single-nucleotide polymorphisms (SNPs) in different genes are reported to be effective in increased risk of CRC in different ethnic population. We conducted a case-control study in patients diagnosed with sporadic colorectal cancer (n = 115) and healthy controls based on colonoscopy evidences (n = 120).In this replicative study, we aimed to investigate the association of two previously reported polymorphisms, rs6983267 and rs4444903, with sporadic colorectal cancer in a subset of Iranian patients. Genotyping was performed via polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay. A significant relation was found between rs6983267 variant in the 8q24 region and colorectal cancer. The distribution of G/G genotypes among sporadic CRC patients was more frequent than that in the control group (P value = 0.001). The frequency of the G allele in the colorectal cancer patient group was also higher than that in the control group (65% vs. 48%; P value = 0.001). Compared with GG genotype, individuals with G/T and T/T genotypes had lower risk to develop sporadic CRC (OR = 0.357, 95% CI = 0.201-0.635). For the rs4444903 SNP, no significant association (P value = 0.149) was found with colorectal cancer risk. In conclusion, our findings suggest that the 8q24 rs6983267 SNP may play a pivotal role in the development of sporadic CRC in Iranian population. Therefore, it may be included as a potential genetic susceptibility marker for sporadic CRC.

Cerebral vein and dural sinus thrombosis in adults in Isfahan, Iran: frequency and seasonal variation.

OBJECTIVE: To estimate the frequency of cerebral vein and dural sinus thrombosis (CVST) and its seasonal variation. METHODS: A clinic-based prospective case-register study was conducted from 2001 to 2004. Hundred and twenty-two consecutive definite CVST patients (26 men and 96 women) treated in two major neurological centres of Isfahan, Iran, were included in the study. Part of examination included an assessment of CVST including conventional angiography and/or magnetic resonance imaging and self-reported medical history. Population data were obtained from the 1996 Iran Census. The mean (standard deviation) age of participants was 35.5 (11.9) years. RESULTS: The annual frequency (95% confidence interval) of CVST was 12.3 (10.1, 14.5) per million in a population of 2,472,751, with higher rate in women than in men [19.9 (15.5, 23.9) women and 5.1 (3.2, 7.1) men] and with increasing age in women (up to 50 years), but not in men. The female/male ratio was 3.9 (2.5-6.0). The monthly frequency of CVST ranged from 0.6 per million (0.1, 1.1) in August to 2.1 (1.2, 3.0) in September. The seasonal CVST rate ranged from 2.2 per million (1.3, 3.2) in summer to 4.3 (3.1, 5.7) in autumn. The differences were statistically significant either for the months or season (P < 0.05). CONCLUSION: The findings of this study show the CVST frequency in adults. More women than men are present with CVST and its frequency increased during autumn.

Comparison of interferon beta products and azathioprine in the treatment of relapsing-remitting multiple sclerosis.

We compared the relative efficacy of interferon beta (IFNbeta) products and azathioprine (AZA) in the treatment of relapsing- remitting multiple sclerosis (RRMS). Ninety-four previously untreated patients of short duration with RRMS were randomly allocated to the two treatment groups. The first group received IFNbeta products (Betaferon,Avonex or Rebif); the second group received AZA for 12 months. Response to treatment was assessed at 3, 6, and 12 months after starting therapy. The mean number of relapse during one year of the study was lower in the AZA group than in the IFNbeta products group (0.28 vs. 0.64, P < 0.05). After 12 months, 57.4% of patients receiving IFNbeta products remained relapse free compared with 76.6% of those given AZA. The Expanded Disability Status Scale (EDSS) decreased by 0.30 units in IFNbeta-treated patients (P < 0.05) and 0.46 in AZAtreated patients (P < 0.001). Treatment with IFNbeta products and AZA significantly reduces the relapse rate and EDSS score in patients with RRMS, while AZA is more effective than the IFNbeta formulations.

Lovastatin effects on bone mineral density in postmenopausal women with type 2 diabetes mellitus.

The objective of this study was to examine the effects of lovastatin on bone mineral density (BMD) of postmenopausal women with type 2 diabetes mellitus (DM). The study was an open-label clinical trial conducted from March 2002 to November 2003. Fifty-five postmenopausal women age 54-67 years with type 2 DM were allocated to lovastatin-treated and control (without lovastatin) groups based on low-density lipoprotein cholesterol (LDL-C) >130 or < or =130 mg/dl. The first group received lovastatin (20 mg daily titrated every 3 months to keep LDL-C less than 130 mg/dl) for a total of 18 months. The second group received their own diabetic regimen without statin. The BMD of the lumbar spine (L1 - L4), femoral neck, Wards triangle, trochanter and total hip was measured by dual-energy X-ray absorptiometry at baseline and after 18 months. In the 28 women treated with lovastatin, the BMD increased in lumbar spine (from 0.946 (0.122) to 0.978 (0.135) g/cm2, p<0.01) and Ward's triangle (from 0.685 (0.123) to 0.780 (0.186) g/cm2, p<0.01). In the 27 women not treated with statin, the changes in BMD at all bone sites were not statistically significant. BMD was higher in femoral neck (1.2% vs. -2.7%, p<0.05), Ward's triangle (13.9% vs. 3.3%, p<0.05), trochanter (-0.1% vs. -2.9%, p<0.05), total hip (1.2% vs. -1.4%, p<0.05) and lumbar spine (3.4% vs. 1.2%, p>0.05) at the end of the study. Treatment with lovastatin may prevent bone loss in postmenopausal women with type 2 DM.

Peripheral neuropathy in type 2 diabetes mellitus in Isfahan, Iran: prevalence and risk factors.

BACKGROUND: To estimate the prevalence and risk factors of peripheral neuropathy (PN) in people with type 2 diabetes mellitus. METHODS: A total of 810 patients with type 2 diabetes (289 men and 521 women) from Isfahan Endocrinology and Metabolism Research Centre outpatient clinics, Iran, were examined. Part of examination included an assessment of neurological function including neuropathic symptoms and physical signs and nerve conduction velocity. RESULTS: The prevalence of PN was 75.1% (95% confidence interval 72.1, 78.0). PN was associated with age, proteinuria, and duration of diabetes, insulin-treatment, and presence of any retinopathy and ischaemic heart disease (IHD). The age-adjusted prevalence rate of PN was 78% higher among patients with IHD, 64% higher among patients with any retinopathy, 66% higher among insulin-treated type 2 diabetes, and it was greater with duration of diabetes. Using a stepwise binary logistic regression model, age, duration of diabetes and proteinuria were significant independent predictors of PN. CONCLUSION: Peripheral neuropathy is a common complication in this population of Iranian type 2 diabetic patients. It increases with age, duration of diabetes and proteinuria.

Comparison of Betaferon, Avonex, and Rebif in treatment of relapsing-remitting multiple sclerosis.

OBJECTIVES: To compare the relative efficacies of Betaferon, Avonex, and Rebif in the treatment of relapsing-remitting multiple sclerosis (RRMS). METHODS: Ninety patients with RRMS were randomly allocated to the three treatment groups. The first group received Betaferon, the second group received Avonex, and the third group received Rebif for 24 months. Response to treatment was assessed at 6, 12, and 24 months after start of therapy. RESULTS: Of the 30 patients treated with Betaferon, the mean (standard deviation, SD) of relapse rate decreased from 2.2 (0.7) to 0.7 (0.7) episodes. Correspondingly, in the 30 patients treated with Avonex, the mean (SD) of relapse rate decreased from 2.0 (1.2) to 1.2 (0.9) (P < 0.001). In the 30 patients treated with Rebif, the mean (SD) of relapse rate decreased from 2.4 (1.0) to 0.6 (0.9) (P < 0. 01). After 2 years, 43.3% of patients receiving Betaferon and 56.7% of patients receiving Rebif remained relapse-free compared with 20% of those given Avonex. Expanded Disability Status Scale (EDSS) decreased by 0.7 U in Betaferon-treated patients (P < 0.001), 0.3 U in Rebif-treated patients (P < 0.05), and remained stable in Avonex patients. CONCLUSION: Treatment with Betaferon, Avenox, and Rebif significantly reduce relapse rate and EDSS score in patients with RRMS.

A randomized, double-blind trial of bromocriptine efficacy in nonfluent aphasia after stroke.

The authors assessed the efficacy of bromocriptine in nonfluent aphasia after stroke in a 16-week, randomized, double-blind, placebo-controlled clinical trial conducted from June 2002 to April 2004. In all 38 patients after 4 months of treatment, improvement in both the bromocriptine and placebo treatment groups was observed (p < 0.001). The analysis of repeated-measures analysis of variance revealed bromocriptine did not improve nonfluent aphasia.

Is neighbourhood deprivation a risk factor for gestational diabetes mellitus?

AIMS: To assess the relationship between neighbourhood deprivation and the rate of gestational diabetes mellitus (GDM) using routinely collected data from a clinical information system, in Plymouth, UK. METHODS: Between 1 January 1996 and 31 December 1997, 3933 women residing within the Plymouth Primary Care Trust (PCT) were screened for GDM using indices of neighbourhood deprivation and prevalence of GDM. Areas (n = 43) were classified according to the Townsend index, measuring material deprivation. Pregnant women with and without GDM were compared. RESULTS: The prevalence of GDM was 1.7%[95%, confidence interval (CI) 1.20, 2.11]. The prevalence of GDM ranged from 1.05% (95% CI 0.60, 1.70) in the most deprived to 2.10% (95%, CI 1.34, 3.13), in the least deprived neighbourhood. Crude rates decreased by 50%[relative prevalence (RP) (95% CI) 0.50 (0.27, 0.94); P = 0.06] amongst those living in the most-deprived compared with those living in the least-deprived areas. Using a stepwise binary logistic regression model, older age at delivery significantly increased the risk of developing GDM. [RP (95%, CI) 1.09, (1.04, 1.13)]. Townsend deprivation score had no significant independent association with GDM when other covariates were considered. CONCLUSION: These data suggest that the neighbourhood context in which women live has no impact on the risk of GDM. Diabet.

Public opinion on smoke-free policies in restaurants and predicted effect on patronage in Hong Kong.

BACKGROUND: The Hong Kong government has proposed legislation for smoke-free policies in all restaurants and bars. This is opposed by certain sections of the catering industry. OBJECTIVE: To assess public opinion on smoke-free restaurants and to estimate changes in patronage. DESIGN: A population based, cross sectional random digit dialling telephone survey conducted from November 1999 to January 2000. SETTING AND PARTICIPANTS: 1077 randomly selected subjects age 15 years or over (response fraction of 81.6%). RESULTS: 68.9% (95% confidence interval (CI) 66.2% to 71.7%) supported a totally smoke-free policy in restaurants. Experiences of discomfort or symptoms from second hand smoke in restaurants were common. The majority (77.2%, 95% CI 74.7% to 79.7%) anticipated no change in their frequency of use of restaurants after a smoke-free policy. Increased use was predicted by 19.7% (95% CI 17.3% to 22.1%) of respondents, whereas 3.2% (95% CI 2.2% to 4.4%) stated that they would dine out less often. In multivariate analyses, non-smokers (adjusted odds ratio (OR) 4.9), people who ate three times or less per week in restaurants as compared to those who ate >10 times per week (OR 2.1), those who had previous experience of discomfort from exposure to passive smoking in restaurants (OR 2.8), or who had avoided restaurants in the past because of smoking (OR 1.9), were more likely to support a totally smoke-free policy in restaurants. Smoke-free policies do not appear to have an adverse effect on restaurants, and may increase business by a considerable margin. CONCLUSION: This comprehensive survey-the first in Asia-shows strong community support for smoke-free dining and predicts an overall increase in the patronage of restaurants after the introduction of legislation for totally smoke-free restaurants.

Iron absorption during recovery from malnutrition.

OBJECTIVE: In infants and children recovering from severe malnutrition, iron deficiency is common, and the ability to absorb iron during such recovery is uncertain. The objective of this study was to determine iron absorption during recovery from malnutrition. METHODS: During the later stages of recovery from malnutrition, erythrocyte incorporation of orally administered 58Fe was determined as a surrogate for iron absorption. Based on four indices, subjects were classified as iron-sufficient, iron-deficient or indeterminate. RESULTS: Of the 25 subjects, 9 were classified as iron sufficient, 5 as indeterminate and 11 as iron deficient; all but 5 had evidence of inflammation or infection. Geometric mean erythrocyte incorporation of 58Fe was 32.0% of the dose in the iron-deficient subjects, which was not significantly different (p = 0.073) than the 13.1% in the iron-sufficient subjects. Incorporation of 58Fe by the iron-sufficient subjects did not differ significantly from that by normal subjects in the same age range. Surprisingly, we found no correlation of erythrocyte incorporation of 58Fe and reticulocyte count. CONCLUSIONS: Even in the presence of infection or inflammation, iron absorption by children during a late stage of recovery from malnutrition is not impaired.

Incidence of and risk factors for diabetic retinopathy in diabetic clinic attenders.

The incidence and risk factors for the development of diabetic retinopathy during a mean (SD) follow-up period of 4.6 (2.9) (range 1-12.4) years have been examined among 3424 patients (1878 males and 1546 females) with diabetes mellitus from three outpatient clinics at the University Hospital, Nottingham. The mean (SD) age of participants was 49.2 (17.9) years with a mean (SD) duration of diabetes of 7.3 (9.0) years at initial registration. Among the 3424 patients free of retinopathy at initial registration who attended the clinic at least twice in the period 1979-1992, the incidence of any retinopathy was 59.6 (57.8 male and 61.8 female) per 1000 person-years based on 15,571 person-years of follow-up. The incidence rate of retinopathy was 72% higher among insulin-treated than among non-insulin-treated noninsulin-dependent diabetes mellitus (NIDDM) clinic attenders. Using a Cox's Proportional Hazards Model for insulin-dependent diabetes (IDDM) and NIDDM (insulin and non-insulin-treated) diabetes separately, longer duration of diabetes, higher systolic blood pressure and poor metabolic control were significant independent predictors of retinopathy for all three groups. Never smoking was a significant independent predictor of retinopathy for the insulin-dependent diabetes groups. Lower body mass index, proteinuria and age were predictors of retinopathy only for non-insulin-treated NIDDM patients. Gender and creatinine had no significant independent association with retinopathy when other covariates were considered. These findings will help the identification of those patients at particular risk of retinopathy so that clinic time for screening of eyes can be appropriately focused.

Incidence of and risk factors for cataract among diabetes clinic attenders.

The incidence of and risk factors for cataract during a mean (standard deviation (SD)) follow-up period of 5.0 (3.0) (range 0.1-12.4) years were examined among 3606 patients (2001 male and 1605 female) with diabetes mellitus from three outpatient clinics at the University Hospital, Nottingham. Among the 3606 patients free of cataract at initial registration who attended the clinic at least twice in the period 1979-1992, the mean (SD) age was 49.2 (17.8) years with a mean (SD) duration of diabetes of 7.6 (9.8) years at initial registration. The incidence of cataract was 10.4 (95% confidence interval (CI), 9.0, 11.9) per 1000 person-years based on 18089 person-years of follow-up. The incidence for females (13.6 (95% CI, 11.0, 16.1)) was greater than in males (8 (95% CI, 6.3, 9. 7)) (P<0.001). The incidence of cataract in insulin-dependent diabetes mellitus (IDDM), non-insulin-treated and insulin-treated non-insulin-dependent diabetes mellitus (NIDDM) were 7.1 (95% CI, 5. 4, 8.9), 11.7 (95% CI, 9.1, 14.3) and 17.8 (95% CI, 12.9, 22.7) per 1000 person-years, respectively. Age-adjustment substantially changed the ordering of risk associated with different types of diabetes. Using a Cox's Proportional Hazards Model for IDDM and NIDDM (insulin and non-insulin-treated) diabetes separately, age and any retinopathy were significant independent predictors of cataract for all groups. Poor metabolic control also was a significant independent predictor of cataract for the IDDM and insulin-treated NIDDM diabetes groups. Duration of diabetes was a significant independent predictor of cataract for the IDDM group. Age at diagnosis of diabetes, systolic and diastolic blood pressure, body mass index, proteinuria, cigarette smoking and creatinine had no significant independent association with cataract when other covariates were considered. These findings will help the identification of those diabetic patients at particular risk of cataract so that clinic time for screening of eyes can be appropriately focused and health care planning for people with diabetes considered.

Incidence of and risk factors for proliferative retinopathy and its association with blindness among diabetes clinic attenders.

BACKGROUND: Proliferative diabetic retinopathy (PDR), a prevalent late-stage complication of diabetes, is associated with severe visual loss. The objectives of this report were to estimate the incidence of and risk factors for PDR using routinely collected data from a clinical information system at University Hospital Nottingham for insulin- and non-insulin-dependent (insulin-treated and non-insulin-treated) diabetes separately. We also attempted to assess the risk of blindness in these diabetes clinic attenders. METHODS: During a mean (standard deviation (SD)) follow-up period of 5.1 (2.9) (range 0.5-12.4) years, 3482 diabetic patients (1915 male and 1567 female) from three outpatient clinics at University Hospital, Nottingham were examined. The mean (SD) age of the participants was 49.3 (17.9) years with a mean duration of diabetes of 7.1 (8.7) years at registration. RESULTS: Among the 3482 patients who attended the clinic at least twice in the period 1979-1992, and who were free of PDR at registration, the overall incidence of PDR was 16.2 per 1000 person-years, based on 17,618 person-years of follow-up. The incidence rate of PDR was nearly three times as high among patients with non-proliferative diabetic retinopathy (NPDR) as in those without any retinopathy (42.1 vs. 15.0 per 1000 person-years). Based on a Cox's Proportional Hazards Model, significant independent predictors of PDR recorded at baseline were glycosylated haemoglobin (HbA1), systolic blood pressure, and longer duration of diabetes for patients without PDR or any retinopathy among insulin-dependent patients. Longer duration of diabetes was the only independent predictor of PDR for patients without PDR or any retinopathy in both insulin- and non-insulin-treated non-insulin-dependent patients. These clinic-based data clearly indicate the higher risk of PDR in non-insulin-dependent patients. Gender, age, BMI, creatinine, proteinuria and cigarette smoking, had no significant independent association with PDR when other covariates were considered in all groups. The risk of blindness was greater among those with PDR than those with NPDR in all three types of diabetes, but was substantial even for those without retinopathy. CONCLUSION: These data are of value in identifying those diabetes clinic attenders who may be most at risk.

Metabolism of selenite in men with widely varying selenium status.

OBJECTIVE: This study was undertaken to investigate the metabolism of selenite in men with life-long intakes of deficient, adequate and excess selenium. METHODS: Stable isotopes of selenium were infused for five hours into Chinese men living in deficient, adequate or excessive selenium areas, and 24-hour urine and blood samples were collected daily for the next seven days. Stable isotopic selenium excretion was determined in urine and in whole plasma and plasma fractions. RESULTS: Even though there was a positive correlation of selenium intake with the urinary excretion of this element, this relationship was not linear over the entire range (deficient, adequate, excessive) of selenium intake. When the urine excretion was normalized internally within each group, a sharp increase in the slope of this relationship was found when long-term intake increased to adequate amounts, but the slope reached a plateau when the daily intake exceeded the adequate group. The plasma selenoprotein P fraction was labeled initially, but the incorporation in the glutathione peroxidase fraction subsequently increased by a small amount. A two-month dietary restriction of selenium of the subjects from the excess area did not result in a reduction of urinary excretion of infused selenite. CONCLUSION: A complex relationship exists between long-term intake of selenium and selenium status, and subjects living in the excess area are more saturated with selenium than anticipated. More than two months of depletion are required to affect urinary excretion of selenium.

Quantitative significance of measuring trimethylselenonium in urine for assessing chronically high intakes of selenium in human subjects.

The purpose of the present study was to investigate the effects of Se restriction on the excretion of Se in men who had consumed high levels of this element during their entire lives. With the use of stable isotopes of Se as selenite, the excretion of methylated Se in urine was investigated in Chinese men (n 10) who had habitual chronic high intakes of this element. The relationship between either urine Se or trimethylselenonium (TMSe) to the estimated long-term Se intake was not linear over the entire range of intake, which was also true for the infusion of labelled selenite. A non-linear relationship was also found between urine TMSe and urine Se both for TMSe arising from catabolism of endogenous body Se and that from infused selenite. The data suggest a close precursor-product relationship of urine Se and its TMSe component based on the nearly identical specific activities for these two selenocompounds. Although dimethylselenide in breath was not measured in the present study, combining urinary TMSe with this breath test may be more useful in the assessment of long-term Se status.