Using the socio-ecological model to appraise perspectives on health workforce retention and intention to leave in Malawi and Tanzania: a qualitative longitudinal study

INTRODUCTION

The chronic health workforce shortage poses a significant setback to achieving universal health coverage. Health authorities continually develop and implement human resources for health policies and interventions to alleviate the crisis, including retention policies. However, the success of such policies and interventions is tangential to the alignment with health workers' expectations. The aim of this study was to explore perspectives on health workforce retention and intention to leave among health workers and policy-makers from rural and remote areas of Malawi and Tanzania.

METHODS

Semi-structured interviews were conducted with 120 participants - 111 rural and remote mid-level health workers, and nine policy-makers in Malawi and Tanzania - for a period of 3 years, 2014-2017. The semi-structured interviews were conducted face to face, and follow-up interviews were conducted through emails or social media. By using the socio-ecological model as a framework for analysis, the emerging themes were mapped out and linked.

RESULTS

Health workers related their perspectives on retention and intention to leave to the individual (intrapersonal), family (interpersonal/microsystem), and community (institutional/mesosystem) factors, whereas policy-makers focused their views mainly on the individual (intrapersonal) factors and retention policies at the national level (macrosystem).

CONCLUSION

Policy-makers and health workers in rural and remote settings in Malawi and Tanzania recognise the factors influencing health workforce retention, and intention to leave at the individual level. However, while policy-makers focus mainly on national-level retention policies, health workers focus on retention aspects related to the family and the surrounding community - a clear misalignment. Therefore, health authorities need to align health policies to health workers' expectations to bridge this gap, improve access to the health workforce in rural and remote populations, and improve health outcomes.

Up-skilling associate clinicians in Malawi in emergency obstetric, neonatal care and clinical leadership: the ETATMBA cluster randomised controlled trial

Background

The ETATMBA (Enhancing Training And Technology for Mothers and Babies in Africa) project-trained associate clinicians (ACs/clinical officers) as advanced clinical leaders in emergency obstetric and neonatal care. This trial aimed to evaluate the impact of training on obstetric health outcomes in Malawi.

Method

A cluster randomised controlled trial with 14 districts of Malawi (8 intervention, 6 control) as units of randomisation. Intervention districts housed the 46 ACs who received the training programme. The primary outcome was district (health facility-based) perinatal mortality rates. Secondary outcomes included maternal mortality ratios, neonatal mortality rate, obstetric and birth variables. The study period was 2011–2013. Mortality rates/ratios were examined using an interrupted time series (ITS) to identify trends over time.

Results

The ITS reveals an improving trend in perinatal mortality across both groups, but better in the control group (intervention, effect −3.58, SE 2.65, CI (−9.85 to 2.69), p=0.20; control, effect −17.79, SE 6.83, CI (−33.95 to −1.64), p=0.03). Maternal mortality ratios are seen to have improved in intervention districts while worsening in the control districts (intervention, effect −38.11, SE 50.30, CI (−157.06 to 80.84), p=0.47; control, effect 11.55, SE 87.72, CI (−195.87 to 218.98), p=0.90). There was a 31% drop in neonatal mortality rate in intervention districts while in control districts, the rate rises by 2%. There are no significant differences in the other secondary outcomes.

Conclusions

This is one of the first randomised studies looking at the effect of structured training on health outcomes in this setting. Notwithstanding a number of limitations, this study suggests that up-skilling this cadre is possible, and could impact positively on health outcomes.

Trial registration number

ISRCTN63294155; Results.

Can training non-physician clinicians/associate clinicians (NPCs/ACs) in emergency obstetric, neonatal care and clinical leadership make a difference to practice and help towards reductions in maternal and neonatal mortality in rural Tanzania? The ETATMBA project

OBJECTIVES

During late 2010, 36 trainees including 19 assistant medical officers (AMOs) 1 senior clinical officer (CO) and 16 nurse midwives/nurses were recruited from districts across rural Tanzania and invited to join the Enhancing Human Resources and Use of Appropriate Technologies for Maternal and Perinatal Survival in the sub-Saharan Africa (ETATMBA) training programme. The ETATMBA project was training associate clinicians (ACs) as advanced clinical leaders in emergency obstetric care. The trainees returned to health facilities across the country with the hope of being able to apply their new skills and knowledge. The main aim of this study was to explore the impact of the ETATMBA training on health outcomes including maternal and neonatal morbidity and mortality in their facilities. Secondly, to explore the challenges faced in working in these health facilities.

DESIGN

The study is a pre-examination/postexamination of maternal and neonatal health indicators and a survey of health facilities in rural Tanzania. The facilities surveyed were those in which ETATMBA trainees were placed post-training. The maternal and neonatal indicators were collected for 2011 and 2013 and the survey of the facilities was in early 2014.

RESULTS

16 of 17 facilities were surveyed. Maternal deaths show a non-significant downward trend over the 2 years (282-232 cases/100,000 live births). There were no significant differences in maternal, neonatal and birth complication variables across the time-points. The survey of facilities revealed shortages in key areas and some are a serious concern.

CONCLUSIONS

This study represents a snapshot of rural health facilities providing maternal and neonatal care in Tanzania. Enhancing knowledge, practical skills, and clinical leadership of ACs may have a positive impact on health outcomes. However, any impact may be confounded by the significant challenges in delivering a service in terms of resources. Thus, training may be beneficial, but it requires an infrastructure that supports it.

A qualitative process evaluation of training for non-physician clinicians/associate clinicians (NPCs/ACs) in emergency maternal, neonatal care and clinical leadership, impact on clinical services improvements in rural Tanzania: the ETATMBA project

OBJECTIVES

The Enhancing Human Resources and Use of Appropriate Training for Maternal and Perinatal Survival in sub-Saharan Africa (ETATMBA) project is training non-physician clinicians as advanced clinical leaders in emergency maternal and newborn care in Tanzania and Malawi. The main aims of this process evaluation were to explore the implementation of the programme of training in Tanzania, how it was received, how or if the training has been implemented into practice and the challenges faced along the way.

DESIGN

Qualitative interviews with trainees, trainers, district officers and others exploring the application of the training into practice.

PARTICIPANTS

During late 2010 and 2011, 36 trainees including 19 assistant medical officers one senior clinical officer and 16 nurse midwives/nurses (anaesthesia) were recruited from districts across rural Tanzania and invited to join the ETATMBA training programme.

RESULTS

Trainees (n=36) completed the training returning to 17 facilities, two left and one died shortly after training. Of the remaining trainees, 27 were interviewed at their health facility. Training was well received and knowledge and skills were increased. There were a number of challenges faced by trainees, not least that their new skills could not be practised because the facilities they returned to were not upgraded. Nonetheless, there is evidence that the training is having an effect locally on health outcomes, like maternal and neonatal mortality, and the trainees are sharing their new knowledge and skills with others.

CONCLUSIONS

The outcome of this evaluation is encouraging but highlights that there are many ongoing challenges relating to infrastructure (including appropriate facilities, electricity and water) and the availability of basic supplies and drugs. This cadre of workers is a dedicated and valuable resource that can make a difference, which with better support could make a greater contribution to healthcare in the country.

What factors influence concordance with medications? Findings from the U.K. Asian Diabetes study

AIMS

To investigate concordance with medication, as assessed at baseline and at 1- and 2-year follow-up, and to examine factors associated with non-concordance in a UK-resident South-Asian population.

METHODS

Data from the UK Asian Diabetes Study were analysed. Concordance with medications was assessed and recorded at three time points during the study. Multiple logistic regression was used to investigate the factors associated with non-concordance; the associations of baseline factors with year 1 concordance and baseline plus year 1 factors with year 2 concordance.

RESULTS

Data for 403 patients from seven practices participating in the UK Asian Diabetes Study were analysed. The numbers of patients who were non-concordant were: 63 (16%) at baseline; 101 (25%) at year 1; and 122 (30%) at year 2. The baseline-measured variables that were significantly associated with year 1 non-concordance included diabetes duration, history of cardiovascular disease, components of the EuroQol quality of life questionnaire, the EQ-5D score, and number of medications prescribed. In multivariable analyses, the most important determinant of year 1 non-concordance was baseline non-concordance: odds ratio 13.6 (95% confidence limits 4.7, 39.9). Number of medications prescribed for blood pressure control was also significant: odds ratio 1.8 (95% confidence limits 1.4, 2.4). Similar results were observed for year 2 non-concordance.

CONCLUSIONS

Non-concordance with medications was common and more likely in people prescribed more medications. The current target-driven management of risk factor levels may lead to increasing numbers and doses of medications. Considering the high cost of medications and the implications of poor health behaviours on morbidity and mortality, further investigation of prescribing behaviours and the factors affecting patient concordance are required.

Can training in advanced clinical skills in obstetrics, neonatal care and leadership, of non-physician clinicians in Malawi impact on clinical services improvements (the ETATMBA project): a process evaluation

OBJECTIVES

The 'enhancing human resources and the use of appropriate technologies for maternal and perinatal survival in sub-Saharan Africa' (ETATMBA) project is training emergency obstetric and new-born care (EmONC) non-physician clinicians (NPCs) as advanced clinical leaders. Our objectives were to evaluate the implementation and changes to practice.

DESIGN

A mixed methods process evaluation with the predominate methodology being qualitative.

SETTING

Rural and urban hospitals in 8 of the 14 districts of northern and central Malawi.

PARTICIPANTS

54 EmONC NPCs with 3 years' plus experience.

INTERVENTION

Training designed and delivered by clinicians from the UK and Malawi; it is a 2-year plus package of training (classroom, mentorship and assignments).

RESULTS

We conducted 79 trainee interviews over three time points during the training, as well as a convenience sample of 10 colleagues, 7 district officers and 2 UK obstetricians. Trainees worked in a context of substantial variation in the rates of maternal and neonatal deaths between districts. Training reached trainees working across the target regions. For 46 trainees (8 dropped out of the course), dose delivered in terms of attendance was high and all 46 spent time working alongside an obstetrician. In early interviews trainees recalled course content unprompted indicating training had been received. Colleagues and district officers reported cascading of knowledge and initial changes in practice indicating early implementation. By asking trainees to describe actual cases we found they had implemented new knowledge and skills. These included life-saving interventions for postpartum haemorrhage and eclampsia. Trainees identified the leadership training as enabling them to confidently change their own practice and initiate change in their health facility.

CONCLUSIONS

This process evaluation suggests that trainees have made positive changes in their practice. Clear impacts on maternal and perinatal mortality are yet to be elucidated.

Insulin regulates the novel adipokine adipolin/CTRP12: in vivo and ex vivo effects

There has been intense interest in the adipokines of the C1q complement/TNF-related protein (CTRP) superfamily. Adipolin (CTRP12) has been described as a novel adipokine, abundantly expressed in adipose tissue with insulin-sensitising and anti-inflammatory effects. We wanted to investigate the effects of acute and chronic hyperinsulinaemia on circulating adipolin concentrations (ELISA) via a prolonged insulin-glucose infusion in humans. We also examined the effects of insulin and the insulin sensitiser, rosiglitazone, on adipolin concentrations (western blotting) in human adipose tissue explants. We found that hyperinsulinaemic induction in healthy lean human subjects significantly increased circulating levels of adipolin (P<0.05 and P<0.01). Furthermore, in subcutaneous adipose tissue explants, insulin significantly increased adipolin protein expression and secretion (P<0.05 and P<0.01). This effect was attenuated by the phosphatidylinositol 3-kinase inhibitor, LY294002 (P<0.05). Moreover, the insulin-sensitising peroxisome proliferator-activated receptor γ (PPARγ) agonist, rosiglitazone, significantly increased adipolin protein expression and secretion in subcutaneous adipose tissue explants (P<0.05 and P<0.01). This effect was inhibited by the PPARγ antagonist, GW9662 (P<0.05). Our data provide novel insights into adipolin physiology in human subjects.

The impact of training non-physician clinicians in Malawi on maternal and perinatal mortality: a cluster randomised controlled evaluation of the enhancing training and appropriate technologies for mothers and babies in Africa (ETATMBA) project

Background

Maternal mortality in much of sub-Saharan Africa is very high whereas there has been a steady decline in over the past 60 years in Europe. Perinatal mortality is 12 times higher than maternal mortality accounting for about 7 million neonatal deaths; many of these in sub-Saharan countries. Many of these deaths are preventable. Countries, like Malawi, do not have the resources nor highly trained medical specialists using complex technologies within their healthcare system. Much of the burden falls on healthcare staff other than doctors including non-physician clinicians (NPCs) such as clinical officers, midwives and community health-workers. The aim of this trial is to evaluate a project which is training NPCs as advanced leaders by providing them with skills and knowledge in advanced neonatal and obstetric care. Training that will hopefully be cascaded to their colleagues (other NPCs, midwives, nurses).

Methods/design

This is a cluster randomised controlled trial with the unit of randomisation being the 14 districts of central and northern Malawi (one large district was divided into two giving an overall total of 15). Eight districts will be randomly allocated the intervention. Within these eight districts 50 NPCs will be selected and will be enrolled on the training programme (the intervention). Primary outcome will be maternal and perinatal (defined as until discharge from health facility) mortality. Data will be harvested from all facilities in both intervention and control districts for the lifetime of the project (3–4 years) and comparisons made. In addition a process evaluation using both quantitative and qualitative (e.g. interviews) will be undertaken to evaluate the intervention implementation.

Discussion

Education and training of NPCs is a key to improving healthcare for mothers and babies in countries like Malawi. Some of the challenges faced are discussed as are the potential limitations. It is hoped that the findings from this trial will lead to a sustainable improvement in healthcare and workforce development and training.

Trial registration

ISRCTN63294155

A cluster randomized controlled trial of the effectiveness and cost-effectiveness of intermediate care clinics for diabetes (ICCD): study protocol for a randomized controlled trial

Background

World-wide healthcare systems are faced with an epidemic of type 2 diabetes. In the United Kingdom, clinical care is primarily provided by general practitioners (GPs) rather than hospital specialists. Intermediate care clinics for diabetes (ICCD) potentially provide a model for supporting GPs in their care of people with poorly controlled type 2 diabetes and in their management of cardiovascular risk factors. This study aims to (1) compare patients with type 2 diabetes registered with practices that have access to an ICCD service with those that have access only to usual hospital care; (2) assess the cost-effectiveness of the intervention; and (3) explore the views and experiences of patients, health professionals and other stakeholders.

Methods/Design

This two-arm cluster randomized controlled trial (with integral economic evaluation and qualitative study) is set in general practices in three UK Primary Care Trusts. Practices are randomized to one of two groups with patients referred to either an ICCD (intervention) or to hospital care (control).

Intervention group: GP practices in the intervention arm have the opportunity to refer patients to an ICCD - a multidisciplinary team led by a specialist nurse and a diabetologist. Patients are reviewed and managed in the ICCD for a short period with a goal of improving diabetes and cardiovascular risk factor control and are then referred back to practice.

or

Control group: Standard GP care, with referral to secondary care as required, but no access to ICCD.

Participants are adults aged 18 years or older who have type 2 diabetes that is difficult for their GPs to control. The primary outcome is the proportion of participants reaching three risk factor targets: HbA_1c (≤7.0%); blood pressure (<140/80); and cholesterol (<4 mmol/l), at the end of the 18-month intervention period. The main secondary outcomes are the proportion of participants reaching individual risk factor targets and the overall 10-year risks for coronary heart disease(CHD) and stroke assessed by the United Kingdom Prospective Diabetes Study (UKPDS) risk engine. Other secondary outcomes include body mass index and waist circumference, use of medication, reported smoking, emotional adjustment, patient satisfaction and views on continuity, costs and health related quality of life. We aimed to randomize 50 practices and recruit 2,555 patients.

Discussion

Forty-nine practices have been randomized, 1,997 patients have been recruited to the trial, and 20 patients have been recruited to the qualitative study. Results will be available late 2012.

Trial registration

[ClinicalTrials.gov: Identifier NCT00945204]

An FTO variant is associated with Type 2 diabetes in South Asian populations after accounting for body mass index and waist circumference

AIMS

A common variant, rs9939609, in the FTO (fat mass and obesity) gene is associated with adiposity in Europeans, explaining its relationship with diabetes. However, data are inconsistent in South Asians. Our aim was to investigate the association of the FTO rs9939609 variant with obesity, obesity-related traits and Type 2 diabetes in South Asian individuals, and to use meta-analyses to attempt to clarify to what extent BMI influences the association of FTO variants with diabetes in South Asians.

METHODS

We analysed rs9939609 in two studies of Pakistani individuals: 1666 adults aged ≥40 years from the Karachi population-based Control of Blood Pressure and Risk Attenuation (COBRA) study and 2745 individuals of Punjabi ancestry who were part of a Type 2 diabetes case-control study (UK Asian Diabetes Study/Diabetes Genetics in Pakistan; UKADS/DGP). The main outcomes were BMI, waist circumference and diabetes. Regression analyses were performed to determine associations between FTO alleles and outcomes. Summary estimates were combined in a meta-analysis of 8091 South Asian individuals (3919 patients with Type 2 diabetes and 4172 control subjects), including those from two previous studies.

RESULTS

In the 4411 Pakistani individuals from this study, the age-, sex- and diabetes-adjusted association of FTO variant rs9939609 with BMI was 0.45 (95%CI 0.24-0.67) kg/m(2) per A-allele (P=3.0 × 10(-5) ) and with waist circumference was 0.88 (95% CI 0.36-1.41) cm per A-allele (P=0.001). The A-allele (30% frequency) was also significantly associated with Type 2 diabetes [per A-allele odds ratio (95%CI) 1.18 (1.07-1.30); P=0.0009]. A meta-analysis of four South Asian studies with 8091 subjects showed that the FTO A-allele predisposes to Type 2 diabetes [1.22 (95%CI 1.14-1.31); P=1.07 × 10(-8) ] even after adjusting for BMI [1.18 (95%CI 1.10-1.27); P=1.02 × 10(-5) ] or waist circumference [1.18 (95%CI 1.10-1.27); P=3.97 × 10(-5) ].

CONCLUSIONS

The strong association between FTO genotype and BMI and waist circumference in South Asians is similar to that observed in Europeans. In contrast, the strong association of FTO genotype with diabetes is only partly accounted for by BMI.

Replication of 13 genome-wide association (GWA)-validated risk variants for type 2 diabetes in Pakistani populations

AIMS/HYPOTHESIS

Recent genome-wide association (GWA) studies and subsequent replication studies have greatly increased the number of validated type 2 diabetes susceptibility variants, but most of these have been conducted in European populations. Despite the high prevalence of the disease in South Asians, studies investigating GWA-validated type 2 diabetes risk variants in this ethnic group are limited. We investigated 30 single nucleotide polymorphisms (SNPs), predominantly derived from recent GWA studies, to determine if and to what extent these variants affect type 2 diabetes risk in two Punjabi populations, originating predominantly from the District of Mirpur, Pakistan.

METHODS

Thirty SNPs were genotyped in 1,678 participants with type 2 diabetes and 1,584 normoglycaemic control participants from two populations; one resident in the UK and one indigenous to the District of Mirpur.

RESULTS

SNPs in or near PPARG, TCF7L2, FTO, CDKN2A/2B, HHEX/IDE, IGF2BP2, SLC30A8, KCNQ1, JAZF1, IRS1, KLF14, CHCHD9 and DUSP9 displayed significant (p < 0.05) associations with type 2 diabetes, with similar effect sizes to those seen in European populations. A constructed genetic risk score was associated with type 2 diabetes (p = 5.46 × 10(-12)), BMI (p = 2.25 × 10(-4)) and age at onset of diabetes (p = 0.002).

CONCLUSIONS/INTERPRETATION

We have demonstrated that 13 variants confer an increased risk of type 2 diabetes in our Pakistani populations; to our knowledge this is the first time that SNPs in or near KCNQ1, JAZF1, IRS1, KLF14, CHCHD9 and DUSP9 have been significantly associated with the disease in South Asians. Large-scale studies and meta-analyses of South Asian populations are needed to further confirm the effect of these variants in this ethnic group.

Impact of acute hyperglycaemia on endothelial function and retinal vascular reactivity in patients with Type 2 diabetes

AIM

  In diabetes, endothelial dysfunction and an altered retinal blood flow have been reported and precede overt macrovascular and microvascular disease. Furthermore, an association between postprandial hyperglycaemia, retinopathy and cardiovascular disease has been observed.

METHODS

  Endothelial function and retinal vascular reactivity have been measured in baseline conditions in 10 healthy control subjects and 21 patients with Type 2 diabetes. In the patients with Type 2 diabetes, endothelial function and retinal vascular reactivity have been also measured every hour, for 4 h, during an oral glucose tolerance test. Endothelial function has been evaluated by measuring flow-mediated vasodilation of the brachial artery, while retinal vascular reactivity has been measured using a retinal vessel analyser, during a flicker.

RESULTS

  At 1 and 2 h after glucose ingestion, endothelial function decreased (P<0.05), while retinal vascular reactivity increased, even at 3 h (P<0.05), vs. the baseline values.

CONCLUSION

  Our data highlight that acute hyperglycaemia impacts on endothelial function simultaneously at both macrovascular and at microvascular levels, inducing functional change, which could contribute towards explaining the clinical evidence of a strong association between postprandial hyperglycaemia, cardiovascular disease and retinopathy.

DPP-IV inhibition enhances the antilipolytic action of NPY in human adipose tissue

CONTEXT

Dipeptidyl peptidase IV (DPP-IV) inactivates the incretin hormone glucagon-like peptide. It can also affect the orexigenic hormone neuropeptide Y (NPY(1-36)) which is truncated by DPP-IV to NPY(3-36), as a consequence NPY's affinity changes from receptor Y1, which mediates the antilipolytic function of NPY, to other NPY receptors. Little is known whether DPP-IV inhibitors for the treatment of type 2 diabetic (T2DM) patients could influence these pathways.

AIMS

To investigate the in vitro effects of NPY with DPP-IV inhibition in isolated abdominal subcutaneous (AbdSc) adipocytes on fat metabolism, and assessment of NPY receptor and DPP-IV expression in adipose tissue (AT).

METHODS

Ex vivo human AT was taken from women undergoing elective surgery (body mass index: 27.5 (mean +/- s.d.) +/- 5 kg/m2, age: 43.7 +/- 10 years, n = 36). Isolated AbdSc adipocytes were treated with human recombinant (rh)NPY (1-100 nM) with and without DPP-IV inhibitor (1 M); glycerol release and tissue distribution of DPP-IV, Y1 and Y5 messenger RNA (mRNA) were measured and compared between lean and obese subjects.

RESULTS AND CONCLUSION

rhNPY reduced glycerol release, an effect that was further enhanced by co-incubation with a DPP-IV inhibitor [control: 224 (mean +/- s.e.) +/- 37 micromol/l; NPY, 100 nM: 161 +/- 27 micromol/l**; NPY 100 nM/DPP-IV inhibitor, 1 M: 127 +/- 14 micromol/l**; **p < 0.01, n = 14]. DPP-IV was expressed in AbdSc AT and omental AT with relative DPP-IV mRNA expression lower in AbdSc AT taken from obese [77 +/- 6 signal units (SU)] vs. lean subjects (186 +/- 29 SU*, n = 10). Y1 was predominantly expressed in fat and present in all fat depots but higher in obese subjects, particularly the AbdSc AT-depot (obese: 1944 +/- 111 SU vs. lean: 711 +/- 112 SU**, n = 10). NPY appears to be regulated by AT-derived DPP-IV. DPP-IV inhibitors augment the antilipolytic effect of NPY in AT. Further studies are required to show whether this explains the lack of weight loss in T2DM patients treated with DPP-IV inhibitors.

Comparison of maternal ghrelin and leptin in healthy mothers and mothers with Type 1 diabetes

AIMS

Maternal leptin affects placental growth hormone (GH), whereas ghrelin, a natural ligand of the growth-hormone-secretagogue receptor, modulates GH action. Both hormones may affect fetal growth, and dysregulation in diabetes may lead to fetal growth disturbances. The aim was to investigate changes in maternal ghrelin during pregnancy with diabetes and to establish reference leptin levels.

METHODS

Twelve healthy non-diabetic (ND) and 12 pregnant women with Type 1 diabetes (T1DM) were recruited. Age and body mass index (BMI) [ND: age 29.9 +/- 4.7 years (mean +/- sd), BMI 25.2 +/- 3.7 kg/m2; T1DM: age 31 +/- 5.5 years, BMI 27 +/- 3.1 kg/m2] were similar in the groups. HbA1c in T1DM was 6.2 +/- 1.1% at 20 weeks, 6.3 +/- 1.1% at 30 weeks' gestation and 7.8 +/- 2.1% postpartum. Fasting plasma ghrelin, total leptin, free leptin (FL) and soluble leptin receptor (sOB-R) levels were measured at 20 and 30 weeks' gestation and postpartum and determined by radioimmunoassay.

RESULTS

All pregnancies resulted in full-term singleton births with no differences in birth weight between groups [T1DM: 3.4 +/- 0.56 kg (mean +/- SE); ND: 3.6 +/- 0.3 kg, P = NS]. Ghrelin levels were lower in T1DM when corrected for age and mothers' weight (T1DM: 458 +/- 36 pg/ml and 432.9 +/- 26.6 pg/ml; ND: 562 +/- 52 pg/ml and 515.8 +/- 63 pg/ml at 20 and 30 weeks, respectively, P < 0.05). T1DM mothers had higher levels of sOB-R and FL levels declined at 30 weeks' gestation in T1DM (P = 0.04) but not in ND.

CONCLUSION

In a population of pregnant women with expected changes in leptin levels as previously reported, ghrelin levels were lower in T1DM pregnancies at 20 and 30 weeks. This may have implications for fetal development and requires further study in diabetes, particularly in pregnancies that result in macrosomia.

Enhanced diabetes care to patients of south Asian ethnic origin (the United Kingdom Asian Diabetes Study): a cluster randomised controlled trial

BACKGROUND

Delivery of high-quality, evidence-based health care to deprived sectors of the community is a major goal for society. We investigated the effectiveness of a culturally sensitive, enhanced care package in UK general practices for improvement of cardiovascular risk factors in patients of south Asian origin with type 2 diabetes.

METHODS

In this cluster randomised controlled trial, 21 inner-city practices in the UK were assigned by simple randomisation to intervention (enhanced care including additional time with practice nurse and support from a link worker and diabetes-specialist nurse [nine practices; n=868]) or control (standard care [12 practices; n=618]) groups. All adult patients of south Asian origin with type 2 diabetes were eligible. Prescribing algorithms with clearly defined targets were provided for all practices. Primary outcomes were changes in blood pressure, total cholesterol, and glycaemic control (haemoglobin A1c) after 2 years. Analysis was by intention to treat. This trial is registered, number ISRCTN 38297969.

FINDINGS

We recorded significant differences between treatment groups in diastolic blood pressure (1.91 [95% CI -2.88 to -0.94] mm Hg, p=0.0001) and mean arterial pressure (1.36 [-2.49 to -0.23] mm Hg, p=0.0180), after adjustment for confounders and clustering. We noted no significant differences between groups for total cholesterol (0.03 [-0.04 to 0.11] mmol/L), systolic blood pressure (-0.33 [-2.41 to 1.75] mm Hg), or HbA1c (-0.15% [-0.33 to 0.03]). Economic analysis suggests that the nurse-led intervention was not cost effective (incremental cost-effectiveness ratio pound28 933 per QALY gained). Across the whole study population over the 2 years of the trial, systolic blood pressure, diastolic blood pressure, and cholesterol decreased significantly by 4.9 (95% CI 4.0-5.9) mm Hg, 3.8 (3.2-4.4) mm Hg, and 0.45 (0.40-0.51) mmol/L, respectively, and we recorded a small and non-significant increase for haemoglobin A1c (0.04% [-0.04 to 0.13]), p=0.290).

INTERPRETATION

We recorded additional, although small, benefits from our culturally tailored care package that were greater than the secular changes achieved in the UK in recent years. Stricter targets in general practice and further measures to motivate patients are needed to achieve best possible health-care outcomes in south Asian patients with diabetes.

Adiponectin complexes in human cerebrospinal fluid: distinct complex distribution from serum

AIMS/HYPOTHESIS

Adiponectin is an adipocyte-derived secretory factor that is specifically produced in adipocytes. It exerts effects on energy homeostasis via peripheral and central mechanisms. However, it is not clear whether adiponectin crosses the blood-brain barrier in humans. In serum, adiponectin circulates in several different complexes, each of which has distinct functions. Here, we wanted to test whether adiponectin can be found in human cerebrospinal fluid (CSF) and whether specific adiponectin complexes are enriched in CSF compared with peripheral serum samples. We also wanted to establish whether there is a sex-related difference with regard to the distribution of adiponectin oligomers in CSF.

MATERIALS AND METHODS

We studied 22 subjects (11 men, 11 women) in this study. Their average BMI was 28.0+/-4.7 kg/m2; average age was 70+/-7 years.

RESULTS

Analysis of total adiponectin revealed that adiponectin protein is present in human CSF at approximately 0.1% of serum concentration. The distribution of adiponectin oligomers differs considerably in CSF from that of serum within matched samples from the same patients. Only the adiponectin trimeric and low-molecular-mass hexameric complexes are found in CSF, with a bias towards the trimeric form in most patients. Male subjects have a higher CSF:serum ratio of total adiponectin (p<0.05; n=20) and have slightly higher trimer levels in serum and CSF than female subjects.

CONCLUSIONS/INTERPRETATION

We conclude that the adiponectin trimer is the predominant oligomer in human CSF.

Evaluation of delivery of enhanced diabetes care to patients of South Asian ethnicity: the United Kingdom Asian Diabetes Study (UKADS)

AIMS

We tested the hypothesis that enhanced care for diabetes, tailored to the needs of the South Asian community with Type 2 diabetes, would improve risk factors for diabetic vascular complications and ultimately reduce morbidity and mortality.

PATIENTS AND METHODS

The study was a cluster randomized controlled trial (RCT) with general practice the unit of randomization. Six West Midlands general practices with a high proportion of South Asian patients were randomized to 'enhanced care' using Asian link workers and extra community diabetes specialist nurse sessions (intervention) or continued standard practice care (control).

RESULTS

Of 401 patients recruited to the study, 361 (90%), comprising 178 from Coventry and 183 from Birmingham were eligible and included in the analyses. The mean age at baseline (standard deviation, SD) was 58.9 (11.7 years) with median (interquartile range; IQR) duration of diabetes 6.5 (3-11) years. At one year follow-up there was a significant difference in reduction of systolic (4.6 mmHg, P = 0.035) and diastolic blood pressure (3.4 mmHg, P = 0.003) and total cholesterol (0.4 mmol/l, P = 0.005), comparing the intervention and control groups. After adjusting for baseline measurement and age, only differential reduction in diastolic blood pressure remained significant. There was no significant change in HbA(1c) and no difference between the groups.

CONCLUSIONS

Using link workers and extra community diabetes specialist nurse input together with treatment protocols in primary care might prove a useful strategy in working towards NSF targets for diabetes management. In this study, small reductions in blood pressure and cholesterol were achieved. Improvement in glycaemic control may require longer and possibly different strategies. Further research is required to evaluate fully the effectiveness, including the costs and longer term sustainability of culturally sensitive initiatives.

Effect of head-out water immersion on serum sodium transport inhibitor and urinary nonadrenaline excretion in pre-menopausal women

The effect of head out water immersion on the excretion of catecholamines and serum sodium transport inhibitor (STI) was studied in healthy young women during the follicular and leuteal phases. Two way ANOVA showed that menstrual cycle had no effect on the excretion of noradrenaline (NA), dopamine (DA) or serum STI. Analysis of pooled data from follicular and leuteal phases showed that immersion caused a significant increase in sodium excretion and serum STI and a significant decrease in urinary NA excretion in healthy young women. After immersion, sodium excretion, DA excretion and serum STI decreased and NA increased.

Cardiorespiratory responses to underwater treadmill walking in healthy females

This study compared the cardiorespiratory responses of eight healthy women (mean age 30.25 years) to submaximal exercise on land (LTm) and water treadmills (WTm) in chest-deep water (Aquaciser). In addition, the effects of two different water temperatures were examined (28 and 36 degrees C). Each exercise test consisted of three consecutive 5-min bouts at 3.5, 4.5 and 5.5 km x h(-1). Oxygen consumption (VO2) and heart rate (HR), measured using open-circuit spirometry and telemetry, respectively, increased linearly with increasing speed both in water and on land. At 3.5 km x h(-1) VO2 was similar across procedures [chi = 0.6 (0.05) l x min(-1)]. At 4.5 and 5.5 km x h(-1) VO2 was significantly higher in water than on land, but there was no temperature effect (WTm: 0.9 and 1.4, respectively; LTm: 0.8 and 0.9 l x min(-1), respectively). HR was significantly higher in WTm at 36 degrees C compared to WTm at 28 degrees C at all speeds, and compared to LTm at 4.5 and 5.5 km x h(-1) (P < or = 0.003). The HR-VO2 relationship showed that at a VO2 of 0.9 l x min(-1) x HR was higher in water at 36 degrees C (115 beats x min[-1]) than either on land (100 beats min[-1]) or in water at 28 degrees C (99 beats x min[-1]). The Borg scale of perceived exertion showed that walking in water at 4.5 and 5.5 km x h(-1) was significantly harder than on land (WTm: 11.4 and 14, respectively; LTm: 9.9 and 11, respectively; P < or = 0.001). These cardiorespiratory changes occurred despite a slower cadence in water (the mean difference at all speeds was 27 steps/min). Thus, walking in chest-deep water yields higher energy costs than walking at similar speeds on land. This data has implications for therapists working in hydrotherapy pools.

Functional importance of platelet-derived growth factor (PDGF) receptor extracellular immunoglobulin-like domains. Identification of PDGF binding site and neutralizing monoclonal antibodies

The biological effects of platelet-derived growth factor (PDGF) are mediated by alpha- and beta-PDGF receptors (PDGFR), which have an intracellular tyrosine kinase domain and an extracellular region comprising five immunoglobulin-like domains (D1-D5). Using deletion mutagenesis we mapped the PDGF binding site in each PDGFR to the D2-D3 region. In the case of alpha-PDGFR, 125I-PDGF AA and 125I-PDGF BB bound to the full-length extracellular domain, D1-D5, and D2-D3 with equal affinity (Kd = 0.21-0.42 nM). Identical results were obtained for 125I-PDGF BB binding to beta-PDGFR mutants D1-D5 and D2-D3, establishing that D1, D4, and D5 do not contribute to PDGF binding. Monoclonal antibodies (mAb) directed against individual PDGFR Ig-like domains were used to extend these observations. The anti-D1 mAb 1E10E2 and anti-D5 mAb 2D4G10 had no effect on alpha- or beta-PDGFR function, respectively. In contrast, mAb 2H7C5 and 2A1E2 directed against D2 of the alpha- and beta-receptor, respectively, blocked PDGF binding, receptor autophosphorylation and mitogenic signaling with IC50 values of 0.1-3.0 nM. An anti-D4 mAb 1C7D5 blocked beta-receptor autophosphorylation and signaling without inhibiting PDGF binding consistent with the observation that D4 is essential for PDGFR dimerization (Omura, T., Heldin, C.-H., and Ostman, A. (1997) J. Biol. Chem. 272, 12676-12682). mAbs identified here act as potent PDGFR antagonists that can be used as research tools and potentially as therapeutic agents for the treatment of diseases involving unwanted PDGFR signaling.

Screening for diabetic retinopathy in primary care: retinal photography alone can be used efficiently and effectively to exclude those with sight threatening lesions

BACKGROUND

Good screening performance of retinal photography and ophthalmoscopy together in screening for diabetic retinopathy in primary care have been reported. This study reanalysed the data to evaluate the screening performance of photography alone.

METHODS

One thousand and ten patients screened by fundal photography and ophthalmoscopy were studied retrospectively. Fundal photographs were quality graded with poor quality pictures being excluded from the analysis. Each patient was reviewed initially by both retinal photographs and ophthalmoscopy by an ophthalmologist, the "gold standard". Six months later the fundal photographs were reviewed and reported in a blinded manner by the ophthalmologist.

RESULTS

Two thousand and fourteen photographs were obtained, of which 162 (8%) had to be excluded because of poor quality. On review of the remaining 1852 photographs in isolation, of 77 cases of severe retinopathy as determined by the "gold standard", 67 had severe changes on photography--detection rate 87%. Of the 1775 cases without sight threatening retinopathy only five were judged to have sight threatening changes on photography--false positive rate 0.3%. Considering sight threatening and background retinopathy together, the detection rate was 69% (257 of 375) and the false positive rate 1.6% (23 of 1477).

CONCLUSION

Good quality fundal photographs alone seem specific enough to screen for sight threatening diabetic retinopathy, but will underdetect background retinopathy.

Adding retinal photography to screening for diabetic retinopathy: a prospective study in primary care

OBJECTIVE

To evaluate whether adding retinal photography improved community screening for diabetic retinopathy.

SETTING

Mobile screening unit at rural and urban general practices in south west England.

SUBJECTS

1010 diabetic patients from primary care.

DESIGN

Prospective study; patients were examined by ophthalmoscopy by general practitioners or opticians without fundal photographs and again with photographs, and assessments were compared to those of an ophthalmologist.

MAIN OUTCOME MEASURES

Whether fundal photography improved the sensitivity of detection of retinopathy and referrable diabetic retinopathy, and whether this sensitivity could be improved by including a review of the films by the specialist.

RESULTS

Diabetic retinopathy was detected by the ophthalmologist in 205 patients (20.5%) and referrable retinopathy in 49 (4.9%). The sensitivity of the general practitioners and opticians for referrable retinopathy with ophthalmoscopy was 65%, and improved to 84% with retinal photographs. General practitioners' sensitivity in detecting background retinopathy improved with photographs from 22% to 65%; opticians' sensitivity in detecting background retinopathy improved from 43% to 71%. The sensitivity of detecting referrable retinopathy by general practitioners improved from 56% to 80% with photographs; for opticians it improved from 75% to 88%.

CONCLUSIONS

Combining modalities of screening by providing photography with specialist review of all films in addition to direct ophthalmoscopy through dilated pupils improves assessment and referral for diabetic retinopathy by general practitioners and opticians. With further training and experience, primary care screeners should be able to achieve a sensitivity that will achieve an effective, acceptable, and economical community based screening programme for this condition.

Abnormal hypothalamic-pituitary-adrenal axis function in rheumatoid arthritis. Effects of nonsteroidal antiinflammatory drugs and water immersion

OBJECTIVE

To investigate the effects of nonsteroidal antiinflammatory drug (NSAID) therapy and water immersion on hypothalamic-pituitary-adrenal (HPA) axis function in rheumatoid arthritis (RA).

METHODS

Plasma levels of adrenocorticotropic hormone (ACTH) and serum and urine levels of cortisol were compared in untreated RA patients, NSAID-treated RA patients, and healthy control subjects.

RESULTS

ACTH levels were significantly higher in untreated RA patients (mean +/- SEM integrated area 11,377 +/- 5,246 hours ng/liter) than in NSAID-treated RA patients (2,285 +/- 388 hours ng/liter) or healthy controls (1,845 +/- 35.5 hours ng/liter) (P < 0.001). Serum and urine cortisol levels were not significantly different between groups. Two-hour head-out water immersion had no effect.

CONCLUSION

Elevated ACTH levels without hypercortisolemia occur in untreated RA. NSAID therapy alters HPA axis response, but immersion has no effect.

Severe deterioration in cognitive function and personality in five patients with long-standing diabetes: a complication of diabetes or a consequence of treatment?

Changes in mood, personality, and social function were examined in a group of five Type 1 diabetic patients, aged 50 to 66 years, with duration of diabetes from 24 to 47 years. Information on medical history was obtained from their carers and hospital records. All patients had experienced multiple episodes of severe hypoglycaemia and had impaired awareness of hypoglycaemia. Cerebral dysfunction predated the development of minimal diabetic complications and had been apparent for between 1 and 17 years. The carers assessed the pre-morbid and present behaviour and personality of the patients using standard questionnaires. Significant deteriorations were demonstrated in cognitive (p = 0.04) and social functions (p = 0.04), compared with assessment of pre-morbid function. Patients had tended to become more neurotic (p = 0.08) and less extravert (p = 0.07). All of the patients and three of the carers recorded scores suggestive of psychiatric morbidity on the General Health Questionnaire. The patients had experienced loss of employment and the carers described a reduction in the patients' social interactions. Although the aetiology of their cerebral dysfunction can not be definitely ascertained this case series emphasizes the need for long-term prospective studies in patients with diabetes of long duration to assess the impact of the disorder on cognitive and social abilities particularly where there is evidence of cerebral dysfunction. The need for professional support for the carers of such patients should be recognized.

Renal sodium retention does not occur during the luteal phase of the menstrual cycle in normal women

OBJECTIVE

To determine whether weight gain due to renal sodium and water retention occurs in the luteal phase of the normal menstrual cycle.

DESIGN

Prospective observational study.

SETTING

Research laboratory installed with modified spa bath.

SUBJECTS

Ten normal healthy women.

INTERVENTION

Each subject underwent two experiments, one in each phase of the menstrual cycle, involving 3 h head-out water immersion and a pre- and post immersion control hour. 25 ml blood samples were obtained every hour before, during and after water immersion.

MAIN OUTCOME MEASURES

Renal and hormonal responses to water immersion during the luteal and proliferative phases of the cycle.

RESULTS

There was no change in weight, creatinine clearance, basal sodium excretion or plasma atrial natriuretic peptide between the two phases of the cycle. There was a significant rise in basal progesterone, plasma aldosterone and plasma renin activity in the luteal phase of the ovulatory cycles. Renal and hormonal responses to immersion including sodium and calcium excretion, elevation of atrial natriuretic peptide (ANP) and suppression of plasma aldosterone and plasma renin activity were identical in the two phases of the menstrual cycle.

CONCLUSION

We found no evidence to support the hypothesis that renal sodium and water retention occurs in the luteal phase of the normal menstrual cycle.

Hypertension and prognosis in established diabetic nephropathy

In the patient with diabetes mellitus the onset of intermittent and then persistent proteinuria signals the development of established nephropathy. This heralds an extremely poor prognosis and mortality in this group has been estimated to be 80 to 100 times greater than that of an age-matched normal population. The excess mortality and its associated morbidity exists for both insulin-dependent and non-insulin-dependent patients who develop proteinuria. The final cause of death is often cardiovascular, such as myocardial infarction or a cerebrovascular accident, rather than end stage renal failure with death from uraemia. Strict and aggressive control of blood pressure during this stage is the only therapy that has been shown to slow the decline in glomerular filtration. To date, there have been no studies large enough to establish if this can produce the desired effect of reducing the excess mortality in this group. The newer antihypertensive agents may have a specific role but this also remains to be shown conclusively; their major advantage may be related to their fewer side-effects especially on cardiovascular risk factors in this highly susceptible group.

Hormonal response to blood volume expansion in diabetic subjects with and without autonomic neuropathy

The hormonal and renal response to volume expansion, produced by water immersion for 4 h, was studied in 14 insulin-dependent diabetic subjects (seven without complications, seven with autonomic neuropathy) and in 14 age-and-sex-matched normal control subjects. The diabetic subjects showed an impaired natriuretic response to volume expansion (total amount of sodium excreted 21 mmol compared to 39 mmol in normals, P less than 0.01) but the response did not differ in those with and without autonomic neuropathy. There was no significant difference in the suppression of plasma renin or aldosterone during immersion in either group. Plasma catecholamines suppressed on immersion in all groups. Basal values were lowest in the group with autonomic involvement. Atrial natriuretic peptide levels showed a twofold rise (from 4.8 to 9.6 pmol/l, P less than 0.01) on immersion. There was no significant difference in the levels of this hormone between diabetic patients and normal subjects or between those diabetics with and those without autonomic neuropathy. The present study confirms that diabetic subjects retain sodium avidly during volume expansion. This enhancement cannot be ascribed to any measurable difference in the levels of circulating hormones known to be involved in natriuresis and is not influenced by the presence of autonomic neuropathy.

Aldose reductase inhibition in diabetic neuropathy: clinical and neurophysiological studies of one year's treatment with sorbinil

In a double-blind placebo-controlled trial the effect of Sorbinil (250 mg daily) on diabetic neuropathy was examined. After a 2-month run-in placebo period (with three major assessments) 21 patients were randomized to Sorbinil and 10 to placebo, and all were studied for a further 12 months with neurophysiological measurements at 3-month intervals of nerve conduction velocity in multiple nerves, autonomic function tests, vibration thresholds as well as clinical examination and an extensive self-assessment of symptoms. Two subjects on Sorbinil treatment developed a hypersensitivity reaction and were withdrawn. Metabolic control and severity of neuropathy was not significantly different between groups. There were no changes in symptoms as judged by self-assessment scores. No patient entered the trial with neuropathic ulcers but ulceration developed in 4 patients during Sorbinil treatment and in 1 of the placebo group. No beneficial effect of Sorbinil was demonstrated on either the clinical manifestation or on the neurophysiological measurements made in these neuropathic diabetic patients over 12 months of treatment.

Bone scintigraphy and radiography in the early recognition of diabetic osteopathy

Twenty-seven diabetic patients with clinical evidence of neuropathy were investigated by foot radiography, two-phase bone scintigraphy, biothesiometry and cardiovascular autonomic function testing. Typical signs of diabetic osteopathy on radiography were found in 10 subjects (37%), the degree of radiographic abnormality correlating with the severity of neurological impairment. Furthermore, all diabetics with evidence of severe neuropathy showed some evidence of osteopathy on foot radiographs. In all 10 cases of diabetic osteopathy diagnosed radiographically, abnormalities were shown on scintigraphy. In addition, five other patients showed scintigraphic abnormalities, without corresponding changes on radiography, and in this group the neurological impairment was less severe. Although confirmatory longitudinal studies are necessary, it seems likely that the earliest changes of diabetic neuropathic osteopathy may thus be recognized on bone scintigraphy, at a time when conventional radiographs are normal. This stage of diabetic osteopathy is associated with a lesser degree of neurological impairment.

Haemodynamic changes in man during immersion in water at different temperatures

1. Stroke volume and cardiac output were measured using the Doppler ultrasound technique in 16 normal subjects immersed to the neck in water at 33 degrees C, 35 degrees C, 37 degrees C and 39 degrees C. A standard aortic diameter was assumed and results were expressed as percentage changes from pre-immersion resting values. 2. Cardiac output rose progressively at higher temperatures, increasing by 30% at 33 degrees C and by 121% at 39 degrees C. At thermoneutral temperatures (33 degrees C and 35 degrees C) this was achieved by an increase in stroke volume of 50% despite a significant decrease in heart rate. There was a further rise in stroke volume and pulse rate at higher temperatures and a mean tachycardia of 109 +/- 4 beats/min was noted at 39 degrees C. Calculated peripheral resistance reduced progressively with increasing temperature of immersion. 3. This non-invasive and simple technique may provide a non-exercise-related cardiovascular stress test to study cardiovascular responses in a variety of pathophysiological states.

The prevalence of autonomic neuropathy in insulin-dependent diabetes mellitus: a controlled study based on heart rate variability

Autonomic function was investigated by tests of heart rate variation in 506 unselected insulin-dependent diabetics aged 12 to 85 years. Heart rate variability was measured by a computerised technique during rest and in response to a single deep breath, the Valsalva manoeuvre and standing. Changes in heart rate were compared with age-related normal ranges derived from 310 non-diabetic control subjects aged 18 to 87 years. Heart rate responses were found to be below the 5th centile control value in 13 to 23 per cent of diabetics. Impaired heart rate variability occurred more frequently in response to a single deep breath than to the other procedures. Results from all four procedures were combined in each subject to give an 'autonomic score', varying from 0 to 4. This score was greater than 1 in only five of 310 (1.6 per cent) non-diabetic control subjects. A score of 2 or more was therefore defined as abnormal and indicative of cardiac autonomic denervation. Abnormal autonomic scores were found in 84 diabetics (16.6 per cent). In diabetic subjects the autonomic score correlated most closely with heart rate variability at rest and in response to a single deep breath. Abnormal autonomic scores correlated significantly with duration of diabetes (p less than 0.0001) but not with age (p = 0.06). The frequency of abnormal autonomic scores was greatest in diabetics aged 40 to 49 years (24.5 per cent) and those with diabetes of 20 or more years duration (30.7 per cent).

Plasma catecholamine levels during water immersion in man

In ten normal subjects thermoneutral neck-out water immersion produced a highly significant natriuresis and diuresis mediated via an induced central hypervolaemia. During immersion suppression of plasma noradrenaline and adrenaline was observed but no change occurred in plasma dopamine levels. No correlation was found between the suppression of noradrenaline and the diuresis and natriuresis. The reduction in plasma noradrenaline observed may reflect a widespread diminution of sympatho-adrenal activity during water immersion. This reduction could be a consequence of the cardiovascular changes of immersion and may not be directly involved in the mechanism of the renal response.

Impaired sodium excretion in response to volume expansion induced by water immersion in insulin-dependent diabetes mellitus

The renal response to volume expansion produced by water immersion to the neck at 35 degrees C was examined in eight young normotensive uncomplicated insulin-dependent diabetic subjects and in eight matched normal control subjects. Both the diabetic and normal subjects manifested a renal response of natriuresis and kaliuresis on immersion, but the natriuretic response was reduced in the diabetic group. Thus the induced excretion of sodium over the 4 h of immersion was 40 +/- 5 mmol (mean +/- SEM) in the normal group compared with 22 +/- 4 mmol in the diabetic group (P less than 0.02). In the normal subjects creatinine clearance did not change during immersion compared with pre-immersion control values while in the diabetic group it rose from pre-immersion control values of 112 +/- 11 ml/min to a mean value of 127 +/- 11 ml/min during immersion (P less than 0.01). The diabetic subjects thus excreted less sodium despite an increased filtered load during water immersion. Fractional excretion of sodium was significantly reduced in the diabetic subjects compared with the normal control subjects (P less than 0.05). The suppression of plasma renin and aldosterone was similar in normal and diabetic groups. Tubular sodium retention could be an early functional change in the diabetic kidney, and be implicated in the development of diabetic nephropathy.

Atrial natriuretic peptide: physiological release associated with natriuresis during water immersion in man

Thermoneutral water immersion produces a physiological increase of thoracic blood volume, raises central venous pressure and increases urinary sodium excretion by a hitherto ill-understood mechanism. We have investigated whether this enhanced sodium excretion could be mediated by the recently discovered natriuretic factor, atrial natriuretic peptide (ANP). During water immersion there was a highly significant (P less than 0.001) twofold increase of the mean plasma ANP concentration and a doubling of the mean urinary sodium excretion. Both were unchanged during the control experiments. These results are consistent with the hypotheses that ANP is released into plasma in response to central blood volume expansion and that it functions as a natriuretic hormone in normal man under physiological conditions.

Sodium retention in response to saline infusion in uncomplicated diabetes mellitus

The response to a 21 infusion of physiological saline infusion was studied in 7 male uncomplicated insulin-dependent diabetics and in 7 non-diabetic male controls. The urinary sodium excretion in the diabetics in each of the 4 hr following the infusion was approximately half that of the controls. The total induced sodium excretion in controls was 34 +/- 4 mmols (mean +/- SEM) but only 14 +/- 4 mmols in the diabetics (p less than 0.005). The hourly creatinine clearance rate was higher in diabetics than in controls indicating a mechanism of reduced sodium excretion via enhanced tubular reabsorption rather than impaired filtration. This propensity to sodium retention in diabetics may play a role in the tendency to cardiovascular and renal complications.

Abnormal circadian rhythm of melatonin in diabetic autonomic neuropathy

The circadian rhythm of melatonin secretion from the pineal body is entrained to the light-dark cycle and is controlled via sympathetic fibres originating from the superior cervical ganglia. We have therefore examined plasma melatonin profiles in diabetics with and without evidence of autonomic neuropathy and in normal matched controls. The physiological increase in nocturnal plasma melatonin concentration was not observed in diabetics neuropaths. There was no consistent pattern in the diabetics without neuropathy; only three out of the eight subjects in this group had a sustained nocturnal increase in melatonin. Normal diurnal variation of plasma cortisol was present in all groups of subjects. The present study shows that diabetic patients with evidence of autonomic neuropathy lack the normal circadian changes of plasma melatonin concentration. This provides confirmation for the control of pineal function via the sympathetic nervous system in man. The impaired melatonin profiles observed in diabetic patients without apparent autonomic neuropathy suggest that a subclinical state of sympathetic denervation may exist in this group of diabetics.

Does melatonin deficiency cause the enlarged genitalia of the fragile-X syndrome?

Melatonin profiles were studied in five males with cytogenetic and clinical features of the fragile-X syndrome including megalo-orchidia and macrogenitosomia. In comparison with age-matched normal controls, the fragile-X group showed lower melatonin values and a significant impairment of the nocturnal rise in this hormone. Melatonin deficiency may thus be responsible for some of the phenotypic features of this disorder.

Factitious Cushing's syndrome

In this report we describe a patient who produced the clinical and laboratory features of Cushing's syndrome by injecting himself for many months with hydrocortisone. Factitious Cushing's syndrome is a variant of the Münchausen syndrome and should be considered if tests used to establish the diagnosis of Cushing's syndrome appear incongruous particularly in subjects with access to medical intelligence and drugs.

Observations on the effect of immersion in Bath spa water

Immersion in water in spas has been practised for centuries and has many proponents. Despite fierce debate about its efficacy there has been little scientific evaluation of the effect of immersion in mineral waters. Eight normal subjects were immersed in Bath spa water for two hours and the renal, haematological, and cardiovascular responses were compared with those in the control periods before and after immersion. Significant, twofold diuresis and natriuresis, 5% haemodilution, and a 50% increase in cardiac index were observed in subjects immersed, sitting, in Bath spa water at 35 degrees C. These changes may constitute part of the scientific rationale for spa treatment in many states of disease.

Urinary prostaglandin E and antidiuretic hormone during water immersion in man

In 10 normal subjects water immersion to the neck at 35 degrees C produced a highly significant natriuresis and diuresis. Urinary prostaglandin E levels did not change significantly throughout immersion. During the diuresis of water immersion a suppression of urinary antidiuretic hormone occurred.