Danie G. Van Zyl

The effects of social support on health, well-being and management of diabetes mellitus: a black South African perspective

Objectives To determine the underlying dimensions of a social support measure and investigate the effects of social support on health, well-being and management of diabetes mellitus (metabolic control and blood pressure (BP) control). Design A cross-sectional, analytical design was used with a structured questionnaire, comprising demographic characteristics, the MOS Social Support Survey scale and the health perceptions and mental health sub-scales from the SF-20. Setting Two outpatient diabetes mellitus clinics in Pretoria, South Africa. Participants Over a three-month period, the questionnaire was administered to 263 black diabetes mellitus outpatients (174 women and 89 men), aged between 16 and 89 years. The majority of patients (91%) were diagnosed as type 2 diabetes mellitus. Only 22% of the patients had acceptable metabolic control (HbA1c<8.0%), in comparison with 46% who had good BP control (130/85 mmHg). There were significant differences between the clinics on BP control: participants from clinic 1 had better BP control than participants from clinic 2. Results Principal components analysis, followed by an orthogonal (VARIMAX) rotational solution, resulted in two social support factors accounting for 78.9% of the variance. The first factor was labelled socio-emotional support, due to the emphasis on close caring relationships. The second factor was concerned with the more tangible aspects of social support, such as the provision of assistance. Coefficient alpha was 0.97 (socio-emotional support), 0.95 (tangible support) and 0.97 (overall social support). Patients with lower levels of social support had poorer general health and well-being than patients with higher levels of social support. Controlling for clinic, patients with controlled BP had significantly more socio-emotional and tangible support than patients with poor BP control. Conclusions The study demonstrated that: (1) socio-emotional and tangible support were the underlying dimensions of social support; (2) socio-emotional support is an important determinant of health and well-being; and (3) social support is beneficial for one aspect of diabetes mellitus management, namely, BP control.

Glycaemic control improves fibrin network characteristics in type 2 diabetes – A purified fibrinogen model

Diabetic subjects have been shown to have altered fibrin network structures. One proposed mechanism for this is non-enzymatic glycation of fibrinogen due to high blood glucose. We investigated whether glycaemic control would result in altered fibrin network structures due to decreased fibrinogen glycation. Twenty uncontrolled type 2 diabetic subjects were treated with insulin in order to achieve glycaemic control. Twenty age- and body mass index (BMI)-matched non-diabetic subjects were included as a reference group. Purified fibrinogen, isolated from plasma samples was used for analysis. There was a significant decrease in fibrinogen glycation (6.81 to 5.02 mol glucose/mol fibrinogen) with a corresponding decrease in rate of lateral aggregation (5.86 to 4.62) and increased permeability (2.45 to 2.85 x 10(-8) cm(2)) and lysis rate (3.08 to 3.27 microm/min) in the diabetic subjects after glycaemic control. These variables correlated with markers of glycaemic control. Fibrin clots of non-diabetic subjects had a significantly higher ratio of inelastic to elastic deformation than the diabetic subjects (0.10 vs. 0.09). Although there was no difference in median fiber diameter between diabetic and non-diabetic subjects, there was a small increase in the proportion of thicker fibers in the diabetic samples after glycaemic control. Results from SDS-PAGE indicated no detectable difference in factor XIIIa-crosslinking of fibrin clots between uncontrolled and controlled diabetic samples. Diabetic subjects may have altered fibrin network formation kinetics which contributes to decreased pore size and lysis rate of fibrin clots. Achievement of glycaemic control and decreased fibrinogen glycation level improves permeability and lysis rates in a purified fibrinogen model.

The effect of glycaemic control on fibrin network structure of type 2 diabetic subjects

Diabetic subjects have been shown to have altered fibrin network structures. One possible cause may be fibrinogen glycation resulting in altered structure/function properties. We investigated the effect of glucose control on fibrinogen glycation and fibrin network structure in type 2 diabetes. Blood samples were taken from twenty uncontrolled diabetic subjects at baseline to determine the levels of fibrinogen glycation and fibrin network structures. The subjects were then treated with insulin until blood glucose control was achieved before end blood samples were taken. Twenty age- and BMI-matched non-diabetic subjects were included as a reference group. The diabetic subjects had significantly higher mean fibrinogen glycation at baseline than the non-diabetic subjects (7.84 vs. 3.89 mol glucose / mol fibrinogen; p < 0.001). This was significantly reduced during the intervention (7.84 to 5.24 mol glucose / mol fibrinogen; p < 0.0002) in the diabetic group. Both groups had high mean fibrinogen concentrations (4.25 and 4.02 g/l, diabetic and non-diabetic subjects respectively). There was no difference in fibrinogen concentration, porosity, compaction and kinetics of clot formation between the diabetic subjects and non-diabetic subjects at baseline, nor were there any changes during the intervention despite the reduced fibrinogen glycation. Fibrin network characteristics correlated well with fibrinogen but not with any markers of glycaemic control. Improved glycaemic control resulted in decreased fibrinogen glycation but not fibrinogen concentration. It seems as though porosity, compaction and kinetics of clot formation are more related to fibrinogen concentration than fibrinogen glycation in this model.

Diabetes care and complications in primary care in the Tshwane district of South Africa

AIMS To describe the diabetic population receiving primary care from the Tshwane district public health services and to assess the quality of care of members of this population, their level of disease control and the extent of their complications. METHODS A cluster-randomised trial was conducted in 12 primary care clinics in Tshwane district. A total of 599 diabetic patients attending these clinics for review were consecutively interviewed and clinically examined. Data on the care received was also obtained from their clinical records for the previous 12 months. Patients randomised to the active arm of the study were screened for complications. RESULTS The mean age was 58 years and 80.5% had a body mass index (BMI) ≥25 kg/m(2). Sixty-eight percent of patients were female. Acceptable glycaemic control and LDL-cholesterol were found for only 27% and 33% of patients, respectively (HbA1c<7%; LDL<2.5 mmol/l). Despite more than 79% of patients reporting to be hypertensive, 68% of patients had a systolic blood pressure above 130 mmHg and 64% had a diastolic blood pressure above 80 mmHg. Evaluating patient records of the preceding year, screening for eye complications was only reported in 8.2%, feet complications in 6.5%, kidney complications in 21.4% and cardiovascular complications in 7.8%. The screening prevalences found were 29% for retinopathy, 22% for maculopathy, 5% for neuropathy (neurothesiometer), 7% for nephropathy (eGFR stages 3-5), 17% for possible infarction (Rose questionnaire) and 36% for severe erectile dysfunction (SHIM questionnaire). CONCLUSION Diabetes care and screening for complications at primary care level in the Tshwane district were found to be sub-optimal. Measures should be taken to address this.

Comparison of the VersaTREK blood culture system against the Bactec9240 system in patients with suspected bloodstream infections

BackgroundTo evaluate the VersaTREK (TREK Diagnostic Systems, Cleveland, Ohio) blood culture system against the Bactec9240 (BD Microbiology, Cockeysville, MD), for the recovery of bloodstream pathogens.MethodsVenous blood from patients with suspected bacterial sepsis was evenly distributed into bottles of each system. Positive signals were recorded and bottles processed onto standard media for organism recovery. False positive signals were regarded if no organisms were seen on Gram stain and no growth was observed.Results177 bottles were available for analysis; the Bactec9240 system yielded 43 positive, 134 negative results and no false positive signals. The VersaTREK system had 58 positive signals with 14 being false positives.ConclusionsIn our setting with high background burden of immuno-compromised patients, the VersaTREK system compared favourably with the Bactec9240 in recovering blood stream aerobic and facultative anaerobic pathogens from patients with suspected bacterial sepsis. A concern is the high false positivity rate. Due to its versatility to accommodate small and large workloads as well as using smaller volumes of blood, this system may establish itself as a useful alternative for the recovery of bloodstream pathogens.

Management of diabetes mellitus in outpatient facilities is achieving poor results

846 To the Editor: In South Africa, prevalence rates for diabetes mellitus (DM) are rising at an alarming rate. In addition, South African diabetic patients suffer from high rates of obesity, poor blood pressure (BP) control and poor glycaemic control. In order to monitor management of DM, records were examined for 149 patients (76 black and 73 white) attending one of two Tshwane (formerly greater Pretoria) facilities for routine outpatient treatment. Body mass index (BMI), BP and HbA1c results were used to ascertain management of DM. Controlled BMI was defined as < 25 kg/m, controlled systolic and diastolic BP as < 130/85 mmHg and glycaemic control as HbA1c results < 7.0%.

Impact of CYP2D6 genotype on amitriptyline efficacy for the treatment of diabetic peripheral neuropathy : a pilot study

AIM Therapy with low-dose amitriptyline is commonly used to treat painful diabetic peripheral neuropathy. There is a knowledge gap, however, regarding the role of variable CYP2D6-mediated drug metabolism and side effects (SEs). We aimed to generate pilot data to demonstrate that SEs are more frequent in patients with variant CYP2D6 alleles. METHOD To that end, 31 randomly recruited participants were treated with low-dose amitriptyline for painful diabetic peripheral neuropathy and their CYP2D6 gene sequenced. RESULTS Patients with predicted normal or ultra-rapid metabolizer phenotypes presented with less SEs compared with individuals with decreased CYP2D6 activity. CONCLUSION Hence, CYP2D6 genotype contributes to treatment outcome and may be useful for guiding drug therapy. Future investigations in a larger patient population are planned to support these preliminary findings.

Knowledge of foot care in people with diabetes in a tertiary care setting

Background. The objective of this study was to investigate levels of foot care knowledge among patients attending the diabetes clinic at Pretoria Academic Hospital by comparing the knowledge of patients with ‘at risk’ feet (ARF) to those with ‘normal/not at risk’ feet (NARF) and so assess whether the education effort by the clinic is effective. Methods. Patients attending the clinic completed an interviewer-assisted questionnaire with 11 questions concerning foot care knowledge. A knowledge score for each patient was calculated. Results. Possible scores ranged from 4 to 11 (maximum 11). The mean score for the ARF group was 8.9 (standard deviation (SD) 1.4) (range 4–11) compared with 8.9 (SD 1.4) for the NARF group (range 5–11) (p>0.05). The most substantial difference between the two groups was that the ARF group gave 20% more correct answers than the NARF group with regard to frequency of foot inspection (daily) (p=0.025). Conclusions. Both groups of patients had a reasonable knowledge regarding foot care. The patients at risk were more aware of the need for daily foot inspection.

Are we missing at-risk babies? Comparison of customised growth charts v. standard population charts in a diabetic population

Background. Diabetes in pregnancy is associated with both accelerated fetal growth and intrauterine growth restriction. Objective. To compare the difference in occurrence of large-for-gestational-age (LGA) and small-for-gestational-age (SGA) fetuses in a pregnant diabetic population using population-based growth charts and customised growth charts. Methods. Retrospective observational study at Steve Biko Academic and Kalafong hospitals, Pretoria, South Africa. Information from an electronic database was used to retrospectively generate customised centiles using a web-based tool (www.gestation.net). The first fetal growth scan of the third trimester, as determined by ultrasound, was plotted for each patient on both the population-based and customised growth charts. We compared the growth category on the population-based growth chart with the that on the customised growth chart. Results. Of the patients, 44 had type 1 diabetes, 66 type 2 diabetes and 173 gestational diabetes. The growth of 79/283 fetuses would have been reclassified had customised growth charts been used. Of cases in which fetal growth was classified as appropriate for gestation on the population-based growth charts, 58 fetuses would have been LGA and 14 SGA had customised growth charts been used. Four of the fetuses that were SGA and three that were LGA on the population-based growth charts would have been classified as appropriately grown on the customised growth charts. This was a statistically significant difference ( p <0.001), with a Cohen’s kappa of 0.45 indicating moderate agreement. Conclusions. Customised growth charts identified more babies with aberrations of growth, who may need vigilant antenatal care and elective delivery and may be at increased health risk in the future.