Size matters: Associations between the androgen receptor CAG repeat length and the intrafollicular hormone milieu.

Granulosa cell (GC) expressed androgen receptors (AR) and intrafollicular androgens are central to fertility. The transactivating domain of the AR contains a polymorphic CAG repeat sequence, which is linked to the transcriptional activity of AR and may influence the GC function. This study aims to evaluate the effects of the AR CAG repeat length on the intrafollicular hormone profiles, and the gene expression profiles of GC from human small antral follicles. In total, 190 small antral follicles (3-11 mm in diameter) were collected from 58 women undergoing ovarian cryopreservation for fertility preservation. The biallelic mean of the CAG repeat lengths were calculated for each woman, and grouped in three groups: Long CAG repeats (23-26 mean CAG); medium CAG repeats (20.5-22.5 mean CAG) and short CAG repeats (17.5-20.0 mean CAG). The following parameters were measured: follicle diameter, intrafollicular levels of Anti-Müllerian Hormone (AMH), progesterone, oestradiol, testosterone and androstenedione, and GC gene expression levels of FSHR, LHR, AR, CYP19A1, and AMH. The long CAG repeat lengths were associated with significantly decreased testosterone levels, as compared to medium CAG repeats (P = 0.05) and short CAG repeats (P = 0.003). Furthermore, in follicles 3-6 mm in diameter, the long CAG repeats were associated with significantly increased LHR and CYP19A1 gene expression levels compared to short CAG repeat lengths (P = 0.004 and P = 0.04 respectively), and significantly increased LHR expression compared to medium CAG repeat lengths (P = 0.03). In conclusion, long CAG repeat lengths in the AR were associated to significant attenuated levels of androgens and an increased conversion of testosterone into oestradiol, in human small antral follicles.

Outcomes of transplantations of cryopreserved ovarian tissue to 41 women in Denmark.

STUDY QUESTION: What are the results of transplanting cryopreserved ovarian tissue? SUMMARY ANSWER: The transplanted ovarian tissue can last up to 10 years, with no relapses following the 53 transplantations, and the chance of a successful pregnancy is currently around one in three for those with a pregnancy-wish. WHAT IS KNOWN ALREADY: Cryopreservation of ovarian tissue is now gaining ground as a valid method for fertility preservation. More than 36 children worldwide have now been born following this procedure. STUDY DESIGN, SIZE, DURATION: This is a retrospective cohort study of 41 women who had thawed ovarian tissue transplanted 53 times over a period of 10 years, including 1 patient who was lost to follow-up. PARTICIPANTS/MATERIALS, SETTING, METHODS: The 41 Danish women, who had in total 53 transplantations, were followed for ovarian function and fertility outcome. Safety was assessed by monitoring relapse in cancer survivors. MAIN RESULTS, AND THE ROLE OF CHANCE: Among 32 women with a pregnancy-wish, 10 (31%) had a child/children (14 children in total); this included 1 woman with a third trimester on-going pregnancy. In addition, two legal abortions and one second trimester miscarriage occurred. A total of 24 clinical pregnancies were established in the 32 women with a pregnancy-wish. The tissue remained functional for close to 10 years in some cases and lasted only a short period in others. Three relapses occurred but were unlikely to be due to the transplanted tissue. LIMITATIONS, REASONS FOR CAUTION: Self-report through questionnaires with only in-one hospital formalised follow-up of transplanted patients could result in unreported miscarriages. The longevity of the tissue may vary by few months compared with those reported because some patients simply could not remember the date when the tissue became non-functional. WIDER IMPLICATIONS OF THE FINDINGS: Cryopreservation of ovarian tissue is likely to become integrated into the treatment of young women, with cancer, who run a risk of losing their fertility. The full functional lifespan of grafts is still being evaluated, because many of the transplanted women have continued to maintain ovarian activity. Some of our first cases have had tissue functioning for ∼ 10 years.

Distribution and function of 3',5'-Cyclic-AMP phosphodiesterases in the human ovary.

The concentration of the important second messenger cAMP is regulated by phosphodiesterases (PDEs) and hence an attractive drug target. However, limited human data are available about the PDEs in the ovary. The aim of the present study was to describe and characterise the PDEs in the human ovary. Results were obtained by analysis of mRNA microarray data from follicles and granulosa cells (GCs), combined RT-PCR and enzymatic activity analysis in GCs, immunohistochemical analysis of ovarian sections and by studying the effect of PDE inhibitors on progesterone production from cultured GCs. We found that PDE3, PDE4, PDE7 and PDE8 are the major families present while PDE11A was not detected. PDE8B was differentially expressed during folliculogenesis. In cultured GCs, inhibition of PDE7 and PDE8 increased basal progesterone secretion while PDE4 inhibition increased forskolin-stimulated progesterone secretion. In conclusion, we identified PDE3, PDE4, PDE7 and PDE8 as the major PDEs in the human ovary.

Effect of the FSH receptor single nucleotide polymorphisms (FSHR 307/680) on the follicular fluid hormone profile and the granulosa cell gene expression in human small antral follicles.

The most pronounced effects of FSH signalling are potentially displayed in the follicle fluid, which acts as a reservoir for FSH-induced granulosa cell (GC) secreted hormones. This study investigates the effects of two common polymorphisms of FSHR, FSHR 307 (rs6165) and FSHR 680 (rs6166), by evaluating the hormone and gene expression profiles of human small antral follicles collected under physiological conditions in connection with fertility preservation. In total 69 women at various time during the menstrual cycle were included in this study. The intrafollicular hormone content of 179 follicular fluid samples and the gene expression levels of 85 GC samples were correlated to the genotype of both FSHR polymorphisms. The following parameters were evaluated: follicle diameter, levels of Anti-Müllerian hormone (AMH), progesterone, estradiol, testosterone and androstenedione and gene expression levels of FSHR, luteinizing hormone receptor (LHR), androgen receptor, aromatase cytochrome p450 (CYP19A1), AMH and AMH receptor II (AMHR2). There was 100% concordance between the FSHR 307 and the FSHR 680 genotypes: A/A (p.307Thr/Thr and p.680Asn/Asn), A/G (p.307Thr/Ala and p.680Asn/Ser) and G/G (p.307Ala/Ala and p.680Ser/Ser). Considering all follicles, compared with the other genotypes the G/G genotype was associated with significantly elevated gene expression levels for LHR, while AMHR2 gene expression levels were significantly reduced. In follicles 3-6 mm in diameter LHR gene expression was significantly increased, whereas AMH gene expression was significantly reduced for the G/G genotype. In follicles >6 mm, estradiol and CYP19A1 gene expression levels were significantly higher for the G/G genotype. In conclusion, significant changes were observed between the FSHR 307/680 polymorphisms in human small antral follicles collected under physiological FSH conditions.

Soluble urokinase plasminogen activator receptor levels are elevated and associated with complications in patients with type 1 diabetes.

OBJECTIVES: Soluble urokinase plasminogen activator receptor (suPAR) is a marker of inflammation and endothelial dysfunction. We investigated the associations between suPAR and diabetes, including diabetes duration and complications, in patients with type 1 diabetes. DESIGN, SETTING AND SUBJECTS: From 2009 to 2011, 667 patients with type 1 diabetes and 51 nondiabetic control subjects were included in a cross-sectional study at Steno Diabetes Center, Gentofte, Denmark. suPAR levels were measured with an enzyme-linked immunosorbent assay. MAIN OUTCOME MEASURES: The investigated diabetic complications were cardiovascular disease (CVD: previous myocardial infarction, revascularisation, peripheral arterial disease and stroke), autonomic dysfunction (heart rate variability during deep breathing <11 beats min(-1) ), albuminuria [urinary albumin excretion rate (UAER) ≥30 mg/24 h] or a high degree of arterial stiffness (pulse wave velocity ≥10 m s(-1) ). Analyses were adjusted for gender, age, systolic blood pressure, estimated glomerular filtration rate, UAER, glycated haemoglobin (HbA1c ), total cholesterol, body mass index, C-reactive protein, antihypertensive treatment and smoking. RESULTS: Soluble urokinase plasminogen activator receptor levels were lower in control subjects versus all patients, in control subjects versus normoalbuminuric patients (UAER <30 mg/24 h), in normoalbuminuric patients with short (<10 years) versus long diabetes duration and were increased with degree of albuminuria (adjusted P < 0.001 for all). Furthermore, suPAR levels were higher in patients with versus without CVD (n = 144; 21.3%), autonomic dysfunction (n = 369; 59.2%), albuminuria (n = 357; 53.1%) and a high degree of arterial stiffness (n = 298; 47.2%) (adjusted P ≤ 0.024). The adjusted odds ratio (95% confidence interval) values per 1 ln unit increase in suPAR were as follows: 2.5 (1.1-5.7) for CVD: 2.7 (1.2-6.2) for autonomic dysfunction; 3.8 (1.3-10.9) for albuminuria and 2.5 (1.1-6.1) for a high degree of arterial stiffness (P ≤ 0.039). CONCLUSION: The suPAR level is higher in patients with type 1 diabetes and is associated with diabetes duration and complications independent of other risk factors. suPAR is a potential novel risk marker for the management of diabetes.

Ambulatory blood pressure monitoring for risk stratification in obese and non-obese subjects from 10 populations.

Overweight clusters with high blood pressure (BP), but the independent contribution of both risk factors remains insufficiently documented. In a prospective population study involving 8467 participants (mean age 54.6 years; 47.0% women) randomly recruited from 10 populations, we studied the contribution of body mass index (BMI) to risk over and beyond BP, taking advantage of the superiority of ambulatory over conventional BP. Over 10.6 years (median), 1271 participants (15.0%) died and 1092 (12.9%), 637 (7.5%) and 443 (5.2%) experienced a fatal or nonfatal cardiovascular, cardiac or cerebrovascular event. Adjusted for sex and age, low BMI (<20.7 kg m(-2)) predicted death (hazard ratio (HR) vs average risk, 1.52; P<0.0001) and high BMI (> or = 30.9 kg m(-2)) predicted the cardiovascular end point (HR, 1.27; P=0.006). With adjustments including 24-h systolic BP, these HRs were 1.50 (P<0.001) and 0.98 (P=0.91), respectively. Across quartiles of the BMI distribution, 24-h and nighttime systolic BP predicted every end point (1.13 < or = standardized HR < or = 1.67; 0.046 < or = P<0.0001). The interaction between systolic BP and BMI was nonsignificant (P > or = .22). Excluding smokers removed the contribution of BMI categories to the prediction of mortality. In conclusion, BMI only adds to BP in risk stratification for mortality but not for cardiovascular outcomes. Smoking probably explains the association between increased mortality and low BMI.

Which follicles make the most anti-Mullerian hormone in humans? Evidence for an abrupt decline in AMH production at the time of follicle selection.

Anti-Müllerian hormone (AMH) is exclusively produced by granulosa cells (GC) of the developing pre-antral and antral follicles, and AMH is increasingly used to assess ovarian function. It is unclear which size follicles make the most AMH (total content) and are the main contributors to circulating AMH concentrations. To determine AMH gene expression in GC (q-RT-PCR) and follicular AMH production (Elisa and RIA) in relation to follicular development, 87 follicles (3-13 mm diameter) including both GC and the corresponding follicular fluid (FF) were collected in connection with fertility preservation of human ovaries. Further, follicle number and diameter, graded in 1 mm increments, were determined by 3D ultrasound in 113 women in their natural menstrual cycle to determine follicle number and diameter in relation to circulating AMH levels. This study demonstrates for the first time a positive association between AMH gene expression in human and both total follicular fluid AMH (P < 0.02) and follicular fluid AMH concentration (P < 0.01). AMH gene expression and total AMH protein increased until a follicular diameter of 8 mm, after which a sharp decline occurred. In vivo modelling confirmed that 5-8 mm follicles make the greatest contribution to serum AMH, estimated for the first time in human to be 60% of the circulating concentration. Significant positive associations between gene expression of AMH and FSHR, AR and AMHR2 expression (P < 0.00001 for all three) and significant negative association between follicular fluid AMH concentration and CYP19a1 expression were found (P < 0.0001). Both AMH gene expression (P < 0.02) and follicular fluid concentration of AMH (P < 0.00001) correlated negatively with estradiol concentration.

Concentration of activin A and follistatin in follicular fluid from human small antral follicles associated to gene expression of the corresponding granulosa cells.

The present study correlated concentrations of activin A and follistatin in follicular fluid (FF) from human small antral follicles to FF concentrations of AMH, inhibin B, progesterone, and oestradiol and to the mRNA expression of FSH-receptor (FSHR), LH-receptor (LHR), AMH-receptor2 (AMHR2), CYP19a, and androgen-receptor (AR) in the corresponding granulosa cells (GC). FF from 144 follicles (3-12 mm in diameter) was included whereas mRNA expression profiles were established in GC from 66 of the 144 follicles. Levels of follistatin remained constant in relation to follicular diameter, whereas activin A levels increased in follicles exceeding 10 mm in diameter. Levels of activin A and inhibin B showed a highly significant inverse association. Follistatin showed highly significant positive associations with AMH and inhibin B levels and with FSHR and AR gene expression in GC. This study revealed unexpected associations that probably reflect the complicated regulatory mechanisms governing human folliculogenesis.

The immune marker soluble urokinase plasminogen activator receptor is associated with new-onset diabetes in non-smoking women and men.

AIM: To explore the putative association of new-onset diabetes and the soluble urokinase plasminogen activator receptor (suPAR), which is a new and stable plasma marker of immune function and low-grade inflammation. This association has been previously suggested by using the less sensitive International Classification of Disease system to detect incident diabetes in the Danish MONICA 10 cohort. METHODS: The Danish National Diabetes Register enabled more accurate identification of incident diabetes during a median follow-up of 13.8 years in the Danish MONICA 10 cohort (n = 2353 generally healthy individuals). The soluble urokinase plasminogen activator receptor was measured by the ELISA method. To fulfil model assumptions, outcome analyses were stratified by age, and further by smoking, owing to the interaction between the soluble urokinase plasminogen activator receptor and smoking on new-onset diabetes (P < 0.0001). RESULTS: New-onset diabetes (n = 182) was associated with increased soluble urokinase plasminogen activator receptor levels (P = 0.013). Among 699 middle-aged (41 and 51 years) and 564 older (61 and 71 years) non-smokers, participants in the upper soluble urokinase plasminogen activator receptor quartile had a sex- and age-adjusted relative risk of 6.01 (95% CI 2.17-16.6, P < 0.0006) and relative risk of 3.25 (95% CI 1.51-6.98, P = 0.0025), respectively, for new-onset diabetes compared with participants in the lowest quartile. This relationship remained significant after additional adjustments for C-reactive protein and leukocytes or fasting glucose and insulin or BMI (P < 0.05). The soluble urokinase plasminogen activator receptor was not related to incident diabetes among smokers (P ≥ 0.85). CONCLUSIONS: In these explorative analyses, the soluble urokinase plasminogen activator receptor associated independently with incident diabetes in non-smokers, supporting an immune origin of Type 2 diabetes. Competing disease risk may explain lack of association among smokers.

Soluble urokinase plasminogen activator receptor is associated with subclinical organ damage and cardiovascular events.

OBJECTIVE: The soluble urokinase plasminogen activator receptor (suPAR) is a plasma marker of low grade inflammation and has been associated with cardiovascular risk. We wanted to investigate whether suPAR was associated with markers of subclinical organ damage. METHODS: In a population sample of 2038 individuals, aged 41, 51, 61 and 71 years, without diabetes, prior stroke or myocardial infarction, not receiving any cardiovascular, anti-diabetic or lipid-lowering medications, we measured urine albumin/creatinine ratio (UACR), carotid atherosclerotic plaques and carotid/femoral pulse wave-velocity (PWV) together with traditional cardiovascular risk factors and high sensitivity C-reactive protein (hsCRP). RESULTS: suPAR was significantly associated with the presence of plaques (P = 0.003) and UACR (P < 0.001), but not PWV (P = 0.17) when adjusting for age, gender, systolic blood pressure, cholesterol, plasma glucose, waist/hip ratio, smoking and hsCRP. However, suPAR explained only a small part of the variation in the markers of subclinical organ damage (R(2) 0.02-0.04). During a median follow-up of 12.7 years (5th-95th percentile 5.1-13.4 years) a total of 174 composite endpoints (CEP) of cardiovascular death, non-fatal myocardial infarction and stroke occurred. suPAR was associated with CEP independent of plaques, PWV, UACR, and hsCRP as well as age, gender, systolic blood pressure, cholesterol, plasma glucose, waist/hip ratio and smoking with a standardized hazard ratio of 1.16 (95% confidence interval 1.04-1.28, P = 0.006). CONCLUSION: suPAR was associated with subclinical organ damage, but predicted cardiovascular events independent of subclinical organ damage, traditional risk factors and hsCRP. Further studies must investigate whether suPAR plays an independent role in the pathogenesis of cardiovascular disease.

Circulating soluble urokinase plasminogen activator receptor predicts cancer, cardiovascular disease, diabetes and mortality in the general population.

BACKGROUND: Low-grade inflammation is thought to contribute to the development of cardiovascular disease (CVD), type-2 diabetes mellitus (T2D), cancer and mortality. Biomarkers of inflammation may aid in risk prediction and enable early intervention and prevention of disease. OBJECTIVE: The aim of this study was to investigate whether plasma levels of the inflammatory biomarker soluble urokinase plasminogen activator receptor (suPAR) are predictive of disease and mortality in the general population. DESIGN: This was an observational prospective cohort study. Cohort participants were included from June 1993 to December 1994 and followed until the end of 2006. SETTING: General adult Caucasian population. PARTICIPANTS: The MONICA10 study, a population-based cohort recruited from Copenhagen, Denmark, included 2602 individuals aged 41, 51, 61 or 71 years. MEASUREMENTS: Blood samples were analysed for suPAR levels using a commercially available enzyme-linked immunosorbent assay. Risk of cancer (n = 308), CVD (n = 301), T2D (n = 59) and mortality (n = 411) was assessed with a multivariate proportional hazards model using Cox regression. RESULTS: Elevated baseline suPAR level was associated with an increased risk of cancer, CVD, T2D and mortality during follow-up. suPAR was more strongly associated with cancer, CVD and mortality in men than in women, and in younger compared with older individuals. suPAR remained significantly associated with the risk of negative outcome after adjustment for a number of relevant risk factors including C-reactive protein levels. LIMITATION: Further validation in ethnic populations other than Caucasians is needed. CONCLUSION: The stable plasma protein suPAR may be a promising biomarker because of its independent association with incident cancer, CVD, T2D and mortality in the general population.

Health-related quality of life in children and adolescents undergoing surgery for pectus excavatum.

INTRODUCTION: This study evaluated health-related quality of life (HRQoL) in children and adolescents undergoing cosmetic surgery for pectus excavatum (PE) compared to a group of healthy children. METHODS: The Intervention Group consisted of 172 children and adolescents undergoing surgery for PE between 2003 and 2005, aged 8-20 years; 86% were males. A postoperative follow-up study was conducted one to three years after surgery. None of the children had had the metal bar removed when they answered the questionnaires. The Control Group consisted of healthy schoolchildren (n=387), 201 females and 186 males (9-20 years).The generic health-related quality of life questionnaires, the Child Health Questionnaire CHQ-CF87 (child version), and CHQ-PF50 (parent version) were used in both groups. A Nuss assessment questionnaire modified for Adults (NQ-mA) and a single-step questionnaire (SSQ) on quality of life and health status were only used in the Intervention Group; these questionnaires also included questions about the remembered preoperative status. The response rates in the Intervention and Control Groups were 69% and 70%, respectively. RESULTS: The HRQol was significantly better in the Intervention Group compared to the Control Group in 9 out of 14 subscales (CHQ-CF 87): General Health (p<0.05), Physical Functioning, Self-Esteem, Emotional Role, Role Functioning-Physical (p<0.01) and Mental Health, Family Activities, Bodily Pain, Role Functioning-Behavioral (p<0.001). The scores of the children and the parents correlated well in all subscales (rho range from 0.19-0.55, p<0.05-0.001) except for the Role Functioning-Physical scale (rho=0.17). Significant differences between the parent and child scores were found in six scales. The children reported significantly lower scores in Global Behavior, Global Health, Behavior (p<0.05), Bodily Pain (p<0.01), and Mental Health (p<0.001). The parents reported significantly lower scores in the Self Esteem scale (p<0.01). Self-esteem and body concept scored significantly higher postoperatively (p<0.001) in NQ-mA and SSQ. CONCLUSION: HRQol was significantly better in the Intervention Group compared to healthy controls at the same age. In five subscales Self-Esteem, Behavior, Emotional Role, Mental Health and Family Activities, the PE group had a better HRQoL.

Low triglycerides-high high-density lipoprotein cholesterol and risk of ischemic heart disease.

BACKGROUND: A high triglyceride (TG)--low high-density lipoprotein cholesterol (HDL-C) level (TG > or =1.60 mmol/L [> or =142 mg/dL] and HDL-C < or =1.18 mmol/L [< or =46 mg/dL]) is associated with a high risk of ischemic heart disease (IHD), whereas a low TG--high HDL-C level (TG < or =1.09 [< or =97 mg/dL] and HDL-C > or =1.48 mmol/L [> or =57 mg/dL]) is associated with a low risk. Conventional risk factors tend to coexist with high TG--low HDL-C levels. We tested the hypothesis that subjects with conventional risk factors would still have a low risk of IHD if they had low TG--high HDL-C levels. METHODS: Observational cohort study of 2906 men aged 53 to 74 years free of IHD at baseline. RESULTS: During 8 years, 229 subjects developed IHD. Stratified by conventional risk factors-low-density lipoprotein cholesterol level (< or =4.40 mmol/L or >4.40 mmol/L [< or =170 mg/dL or >170 mg/dL] [median value]), hypertensive status (blood pressure >150/100 mm Hg or taking medication), level of physical activity (>4 h/wk or < or =4 h/wk), and smoking status (nonsmokers vs smokers)-the incidence in men with high TG--low HDL-C levels was 9.8% to 12.2% in the low-risk and 12.2% to 16.4% in the high-risk strata; the corresponding values in men with low TG--high HDL-C concentrations were 4.0% to 5.1% and 3.7% to 5.3%, respectively. Based on an estimate of attributable risk, 35% of IHD might have been prevented if all subjects had had low TG--high HDL-C levels. CONCLUSION: Men with conventional risk factors for IHD have a low risk of IHD if they have low TG--high HDL-C levels.

Triglyceride concentration and ischemic heart disease: an eight-year follow-up in the Copenhagen Male Study.

BACKGROUND: The role of triglycerides as a risk factor of ischemic heart disease (IHD) remains controversial. For the present study, we examined the relation between fasting triglycerides and risk of IHD in the Copenhagen Male Study. METHODS AND RESULTS: Baseline measurements of fasting lipids and other IHD risk factors were obtained for 2906 white men (age range, 53 to 74 years) who were initially free of overt cardiovascular disease. During an 8-year follow-up period, 229 men had a first IHD event. Crude cumulative incidence rates of IHD were 4.6% for the lowest, 7.7% for the middle, and 11.5% for the highest third of triglyceride levels (P for trend <.001). Compared with the lowest third level and adjusted for age, body mass index, alcohol, smoking, physical activity, hypertension, non-insulin-dependent diabetes mellitus, social class, and LDL and HDL cholesterol, relative risks of IHD (95% confidence interval) were 1.5 (1.0 to 2.3; P=.05) and 2.2 (1.4 to 3.4; P<.001) for the middle and highest third of triglyceride levels, respectively. When triglyceride levels were stratified by HDL cholesterol levels (triglyceride third multiplied by HDL cholesterol third), a clear gradient of risk of IHD was found with increasing triglyceride levels within each level of HDL cholesterol, including high HDL cholesterol level, which are thought to provide protection against IHD. CONCLUSIONS: In middle-aged and elderly white men, a high level of fasting triglycerides is a strong risk factor of IHD independent of other major risk factors, including HDL cholesterol.

Relation of high TG-low HDL cholesterol and LDL cholesterol to the incidence of ischemic heart disease. An 8-year follow-up in the Copenhagen Male Study.

High triglyceride (TG) and low HDL cholesterol (HDL-C) is the characteristic dyslipidemia seen in insulin-resistant subjects. We examined the role of this dyslipidemia as a risk factor of ischemic heart disease (IHD) compared with that of high LDL cholesterol (LDL-C) in the Copenhagen Male Study. In total 2910 white men, aged 53 to 74 years, free of cardiovascular disease at baseline, were subdivided into four groups on the basis of fasting concentrations of serum TG, HDL-C, and LDL-C. "High TG-low HDL-C" was defined as belonging to both the highest third of TG and the lowest third of HDL-C; this group encompassed one fifth of the population. "High LDL-C" was defined as belonging to the highest fifth of LDL-C. A control group was defined as not belonging to either of these two groups. "Combined dyslipidemia" was defined as belonging to both dyslipidemic groups. Age-adjusted incidence of IHD during 8 years of follow-up was 11.4% in high TG-low HDL-C, 8.2% in high LDL-C, 6.6% in the control group, and 17.5% in combined dyslipidemia. Compared with the control group, relative risks of IHD (95% confidence interval), adjusted for potentially confounding factors or covariates (age, body mass index, alcohol consumption, physical activity, non-insulin-dependent diabetes, hypertension, smoking, and social class), were 1.5 (1.0-2.1), P < .05; 1.3 (0.9-2.0), P = .16; and 2.4 (1.5-4.0), P < .01, in the three dyslipidemic groups, respectively. In conclusion, the present results showed that high TG-low HDL-C, the characteristic dyslipidemia seen in insulin-resistant subjects, was at least as powerful a predictor of IHD as isolated high LDL-C. The results suggest that efforts to prevent IHD should include intervention against high TG-low HDL-C, and not just against hypercholesterolemia.

Insulin resistance and cigarette smoking.

Cigarette smoking is associated with increases in plasma triglycerides and decreases in plasma high density-lipoprotein-cholesterol concentration. These changes not only increase risk of coronary heart disease but also are secondary to resistance to insulin-stimulated glucose uptake or hyperinsulinaemia. To see whether there is a relation between cigarette smoking and insulin-mediated glucose uptake we measured plasma lipid and lipoprotein concentrations, plasma glucose and insulin response to an oral glucose challenge, and insulin-mediated glucose uptake in 40 matched healthy volunteers (20 non-smokers, 20 smokers). Smokers had significantly higher mean (SEM) very-low-density-lipoprotein triglycerides (0.66 [0.10] vs 0.39 [0.03] mmol/l, p less than 0.02) and cholesterol (0.45 [0.06] vs 0.23 [0.04] mmol/l, p less than 0.005) concentrations and lower high-density-lipoprotein cholesterol concentrations (1.16 [0.05] vs 1.51 [0.08] mmol/l, p less than 0.001). Although plasma glucose concentrations in response to the oral glucose load were similar in the two groups, plasma insulin response of the smokers was significantly higher (p less than 0.001). Finally, smokers had higher steady-state plasma glucose concentrations in response to a continuous infusion of glucose, insulin, and somatostatin (8.4 [0.2] vs 5.0 [0.3] mmol/l, p less than 0.001), despite similar steady-state plasma insulin concentrations. The findings show that chronic cigarette smokers are insulin resistant, hyperinsulinaemic, and dyslipidaemic compared with a matched group of non-smokers, and may help to explain why smoking increases risk of coronary heart disease.

The gastric acid secretagogue gastrin-releasing peptide and the inhibitor oxyntomodulin do not exert their effect directly on the parietal cell in the rat.

Previous studies suggested that gastrin-releasing peptide (a neuropeptide found in rat oxyntic mucosa) and oxyntomodulin (a glucagon-containing peptide of mammalian gut) could directly affect the acid secretion of the parietal cells. We therefore studied their effect on gastric acid production in vitro by measuring [14C]-aminopyrine accumulation, a reliable index of H+ generation, in isolated rat parietal cells. However, neither gastrin-releasing peptide nor oxyntomodulin influenced basal acid secretion or histamine-stimulated gastric acid secretion. Electron-microscopic studies of unstimulated and histamine-stimulated parietal cells confirmed that the cells retained the normal morphology of intracellular organelles and that the cells responded to physiological stimulation by marked expansion of the intracellular canaliculi.