Measured Versus Calculated Small Dense LDL-Cholesterol and Cardiometabolic Traits in a South African Population.

Small-dense low density lipoprotein (sdLDL) is increasingly viewed as a marker for evaluating atherogenic risk, however its clinical uptake is hampered by the cumbersomeness of available methods. Consequently, a number of alternative methods for the estimation of sdLDL have been developed and none have been tested in a population from Africa. We evaluated an equation to estimate sdLDL-C from classic lipid parameters in South Africans. This is a cross-sectional study involving 1550 participants in which direct measurement of sdLDL in 237 participants was performed using a homogeneous enzymatic assay. Their mean age (standard deviation, SD) was 54.2 (14.7) years. 156 (65.8%) were normotolerant, 29 (12.2%) prediabetes, 17 (7.2%) screen detected diabetes and 35 (14.8%) known diabetes. Measured sdLDL values ranged from 0.17 to 3.39 versus-1.85 to 2.52 mmol/L calculated sdLDL. There was a significant positive correlation between the two measurements with a Pearson correlation coefficient of 0.659 (95%CI: 0.581-0.726). In a regression model, the adjusted R2 was 0.440 after adding age, 0.441 after further adding gender, then 0.443 with dysglycemia and lastly 0.447 upon adding body mass index. With the exception of HDL-cholesterol levels that decreased across increasing quintiles of calculated sdLDL, our data showed significant correlations between sdLDL and cardiometabolic risk factors, all p values < 0.0001. In conclusion, this study has shown that calculated sdLDL can be efficiently used to approximate population levels of sdLDL; however the modest correlation indicate that at the individual level, it will poorly approximate true sdLDL levels, with possible implications for risk stratification.

Haemoglobin A1c or Glycated Albumin for Diagnosis and Monitoring Diabetes: An African Perspective.

Diabetes mellitus (DM) has reached epidemic proportions across the globe with the largest increases seen in sub-Saharan Africa. Those that are diagnosed are largely poorly controlled. This review summarizes the limitations of the use of glycated haemoglobin (HBA1c) in Africa and current knowledge on the utility of glycated albumin and fructosamine in African patients. The diagnosis and monitoring of DM in African patients may be compromised by associated conditions like sickle cell anaemia, chronic kidney disease and HIV infection. Glycated albumin reflects short term glycaemia and is not affected by many conditions that alter HbA1c. It can be measured enzymatically, and this review discusses methods for analysis, and discusses the advantages and limitations in specific situations with an emphasis on conditions that also affect HbA1c.

Paraoxonase1 genetic polymorphisms in a mixed ancestry African population.

Paraoxonase 1 (PON1) activity is markedly influenced by coding polymorphisms, Q/R at position 192 and M/L at position 55 of the PON1 gene. We investigated the frequencies of these polymorphisms and their effects on PON1 and antioxidant activities in 844 South African mixed ancestry individuals. Genotyping was done using allele-specific TaqMan technology, PON1 activities were measured using paraoxon and phenylacetate, oxidative status was determined by measuring the antioxidant activities of ferric reducing antioxidant power and trolox equivalent antioxidant capacity, and lipid peroxidation markers included malondialdehyde and oxidized LDL. The frequencies of Q192R and L55M were 47.6% and 28.8%, respectively, and the most common corresponding alleles were 192R (60.4%) and 55M (82.6%). The Q192 was significantly associated with 5.8 units' increase in PON1 concentration and 15.4 units' decrease in PONase activity after adjustment for age, sex, BMI, and diabetes, with suggestion of differential effects by diabetes status. The PON1 L55 variant was associated with none of the measured indices. In conclusion, we have shown that the Q192R polymorphism is a determinant of both PON1 concentration and activity and this association appeared to be enhanced in subjects with diabetes.

Comparison of patients with severe COVID-19 admitted to an intensive care unit in South Africa during the first and second wave of the COVID-19 pandemic.

Background: The second wave of coronavirus disease 2019 (COVID-19), dominated by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Beta variant, has been reported to be associated with increased severity in South Africa (SA). Objectives: To describe and compare clinical characteristics, management and outcomes of COVID-19 patients admitted to an intensive care unit (ICU) in SA during the first and second waves. Methods: In a prospective, single-centre, descriptive study, we compared all patients with severe COVID-19 admitted to ICU during the first and second waves. The primary outcomes assessed were ICU mortality and ICU length of stay (LOS). Results: In 490 patients with comparable ages and comorbidities, no difference in mortality was demonstrated during the second compared with the first wave (65.9% v. 62.5%, p=0.57). ICU LOS was longer in the second wave (10 v. 6 days, p<0.001). More female admissions (67.1% v. 44.6%, p<0.001) and a greater proportion of patients were managed with invasive mechanical ventilation than with non-invasive respiratory support (39.0% v. 14%, p<0.001) in the second wave. Conclusion: While clinical characteristics were comparable between the two waves, a higher proportion of patients was invasively ventilated and ICU stay was longer in the second. ICU mortality was unchanged.

Association of the ENPP1 rs997509 polymorphism with obesity in South African mixed ancestry learners.

BACKGROUND: The Ectonucleotide Pyrophosphatase Phosphodiesterasel (ENPP1) polymorphisms have been associated with metabolic traits. There is no data on the effect of ENPP1 in South African children or adults. OBJECTIVE: To investigate the role of K121Q (rs1044498), rs997509 and rs9402349 in obesity and other components of the metabolic syndrome. DESIGN: A case-control study. SUBJECTS: Sixty four obese and 64 lean mixed ancestry learners. SETTING: Western Cape, South Africa. MAIN OUTCOME MEASURE: The ENPP1 rs997509T allele is independently associated with obesity in children of mixed ancestry from South Africa. RESULTS: The T allele frequency of the rs997509 differed significantly between obese and controls, p=0.0100 and increased the risk of being obese, p = 0.0238. Furthermore, the estimated effect of the T allele was an increase of 8.6 cm in waist circumference, 10.2 kg in weight and a corresponding 4.9 kg/m2 in BMI. Individuals carrying both the 121Q and the T allele of rs997509 were more associated with obesity (odds ratio = 3.85, 95% CI: 1.13 to 13.09) whilst those carrying the C allele of rs997509 in the presence of 121Q were likely to be lean with odds ratio of obesity 0.41 (95% CI: 0.19 to 0.87). CONCLUSION: Our findings suggest that ENPP1 polymorphisms may contribute to different metabolic characteristics, all of which are associated with insulin resistance in mixed ancestry children of South Africa. However, a larger study is required to confirm findings of this study.

The impact of COVID-19 on routine patient care from a laboratory perspective.

BACKGROUND: Globally, few studies have examined the effect of the COVID-19 pandemic on routine patient care and follow-up. OBJECTIVES: To evaluate the effect of the COVID-19 response on biochemical test requests received from outpatient departments (OPDs) and peripheral clinics serviced by the National Health Laboratory Service Chemical Pathology Laboratory at Tygerberg Hospital, Cape Town, South Africa (SA). Request volumes were used as a measure of the routine care of patients, as clinical information was not readily available. METHODS: A retrospective audit was conducted. The numbers of requests received from OPDs and peripheral clinics for creatinine, glycated haemoglobin (HbA1c), lipid profiles, thyroid-stimulating hormone (TSH), free thyroxine, free tri-iodothyronine (fT3), serum and urine protein electrophoresis, serum free light chains and neonatal total serum bilirubin were obtained from 1 March to 30 June for 2017, 2018, 2019 and 2020. RESULTS: The biggest impact was seen on lipids, creatinine, HbA1c, TSH and fT3. The percentage reduction between 1 March and 30 June 2019 and between 1 March and 30 June 2020 was 59% for lipids, 64% for creatinine and HbA1c, 80% for TSH and 81% for fT3. There was a noteworthy decrease in overall analyte testing from March to April 2020, coinciding with initiation of level 5 lockdown. Although an increase in testing was observed during June 2020, the number of requests was still lower than in June 2019. CONCLUSIONS: This study, focusing on the short-term consequences of the SA response to the COVID-19 pandemic, found that routine follow-up of patients with communicable and non-communicable diseases was affected. Future studies are necessary to evaluate the long-term consequences of the pandemic for these patient groups.

Oral Microbiome Signatures in Diabetes Mellitus and Periodontal Disease.

Disturbances in the oral microbiome are associated with periodontal disease initiation and progression and diabetes mellitus (DM), but how this contributes to the cause-and-effect relationship between periodontal disease and DM is poorly understood. We examined the bacterial composition in plaque samples from 128 South Africans with periodontal disease across glycemic statuses using 16S rDNA sequencing of regions 2, 3, 4, 6-7, 8, and 9. Of the 9 phyla identified, Firmicutes, Proteobacteria, Bacteroidetes, Fusobacteria, and Actinobacteria made up >98%. Fusobacteria and Actinobacteria were significantly more abundant in subjects with diabetes, while Proteobacteria were less abundant. However, in the presence of gingival bleeding and DM, as compared with DM without gingival bleeding, Actinobacteria were markedly reduced while Bacteroidetes were more abundant. In contrast, no differences in Actinobacteria or Bacteroidetes abundance were observed between DM with and without pocket depth (PD) ≥4 mm. At the genus level, similar changes in relative abundance were observed in the presence of DM and periodontal disease. Our findings remained in conditional logistic regression models adjusted for age, sex, waist circumference, and the 5 most dominant phyla. For example, Actinobacteria significantly increased the odds of diabetes by 10% in subjects with gingival bleeding, while Fusobacteria increased this odd by 14%; yet, among subjects with PD ≥4 mm, Fusobacteria decreased the odds of DM by 47%. Our findings have confirmed the alterations in the composition of the oral microbiota across glycemic statuses as well as different stages of periodontal disease. However, it is not clear whether these differences were the consequence of hyperglycemia or the presence of periodontal diseases. Therefore, we recommend further investigations in a longitudinal study design.

Membrane saturated fatty acids and disease progression in multiple sclerosis patients.

The risk of developing multiple sclerosis is associated with increased dietary intake of saturated fatty acids. We determined the fatty acid composition within the different phospholipid fractions of red blood and peripheral blood mononuclear cell membranes of 31 patients diagnosed with multiple sclerosis and 30 healthy control subjects using gas chromatography. Individual saturated fatty acids were correlated with the severity of neurological outcome as measured by the Kurtzke Expanded Disability Status Scale. Significant increases were found in multiple sclerosis peripheral blood mononuclear cell membrane sphingomyelin C14:0 and phosphatidylinositol C22:0. In the peripheral blood mononuclear cell membranes, C22:0 and C24:0 showed positive correlations, while C14:0, C16:0 and C20:0 showed inverse correlations with the Functional System Scores. In conclusion, this study is in accordance with previous studies that have shown an increase in shorter long-chain SATS in MS patients. In addition, this study also showed that higher C14:0 and C16:0 reflected better disease outcome as demonstrated by the inverse correlation with the EDSS and FSS. We have also characterized the specific SATS, that is, long-chain SATS that may increase the risk of developing MS.

Increase in blood pressure over a 7-year period in a mixed-ancestry South African population.

BACKGROUND: An increase in the prevalence of high blood pressure (BP) has been reported globally and in the South African (SA) population. OBJECTIVES: To investigate temporal changes in absolute BP levels and hypertension prevalence in the mixed-ancestry South Africans. METHODS: Participants were from two independent cross-sectional surveys conducted during 2008/09 (N=928) and 2014/16 (N=1 969) in Bellville South, Cape Town, SA. Participants' eligibility was based on several criteria, including age >20 years and neither bedridden nor pregnant. Data were obtained by administered questionnaires, clinical measurements (BP and anthropometry) and biochemical assessments (oral glucose tolerance tests and cotinine levels). Known hypertension was based on a self-reported history of doctor-diagnosed hypertension and ongoing treatment. Comparison across years was based on the crude prevalence of hypertension as well as direct age-standardised prevalence, based on the SA 2011 mixed-ancestry population distribution, in 10-year age increments. RESULTS: In all, 708 participants (76.3%) in 2008/09 and 1 488 (75.6%) in 2014/16 were female. Between 2008/09 and 2014/16, mean systolic BP increased from 124 to 136 mmHg (absolute mean difference 15 mmHg) and mean diastolic BP from 75 to 85 mmHg (absolute mean difference 9 mmHg) in the overall sample. The prevalence of screen-detected hypertension increased from 11.6% to 24.8%, with a similar increase in males and females, while the prevalence of known cases remained stable. These changes remained significant after adjustment for age and gender. CONCLUSIONS: A rightward shift in absolute BP translated into a significant increase in the prevalence of hypertension over time in this population. The predominant increases in screen-detected hypertension suggest that the deteriorating profile was not matched by efforts to detect and manage individuals with higher-than-optimal BP levels.

Electrophoresis test prevalence, requesting patterns, yield and related bone marrow biopsy findings at a South African tertiary hospital: A 5-year retrospective audit.

BACKGROUND: Studies of electrophoresis testing (serum protein electrophoresis (SPE), urine protein electrophoresis (UPE), immunofixation electrophoresis (IFE)) in a South African (SA) pathology laboratory setting are limited. OBJECTIVES: To evaluate the prevalence, testing pattern and yield of electrophoresis tests performed over a 5-year period in a tertiary academic laboratory and to relate these findings to bone marrow biopsy findings in a few selected cases. METHODS: This was a retrospective audit of all SPE, UPE and IFE tests performed on new and follow-up adult patients (aged ≥18 years) from 2010 to 2015, using data from the Tygerberg Academic Hospital (Cape Town, SA) National Health Laboratory Service hospital information system database. A subgroup analysis of all patients with negative serum (SIFE) and/or urine immunofixation (UIFE) tests who had concurrent bone marrow biopsies close to the time of IFE testing was also performed. RESULTS: A total of 5 086 SPE tests were performed (44.3% were follow-up tests, and of these patients 13.8% had SIFE tests); 1 299 UPE tests were performed (23.3% were follow-up tests, and of these patients 33.6% had UIFE tests). The mean ages of patients who had SIFE and UIFE tests were 59 years (standard deviation (SD) 14.2) and 60 years (SD 15), respectively. The female-to-male ratio was 1.1:1 for both SIFE and UIFE. The negative test yields for SIFE and UIFE were 31.3% and 52.1%, respectively. Bone marrow biopsy findings for patients with negative SIFE tests identified 8 out of the 20 biopsies (40.0%) as positive for myeloma. CONCLUSION: This audit provides baseline data on the prevalence of test requests, their source and the yield of electrophoresis testing in our laboratory. An increasing trend in SIFE and UIFE was evident.

Genetic association studies of obesity in Africa: a systematic review.

Obesity is increasing in Africa, but the underlying genetic background largely remains unknown. We assessed existing evidence on genetic determinants of obesity among populations within Africa. MEDLINE and EMBASE were searched and the bibliographies of retrieved articles were examined. Included studies had to report on the association of a genetic marker with obesity indices and the presence/occurrence of obesity/obesity trait. Data were extracted on study design and characteristics, genetic determinants and effect estimates of associations with obesity indices. According to this data, over 300 polymorphisms in 42 genes have been studied in various population groups within Africa mostly through the candidate gene approach. Polymorphisms in genes such as ACE, ADIPOQ, ADRB2, AGRP, AR, CAPN10, CD36, C7orf31, DRD4, FTO, MC3R, MC4R, SGIP1 and LEP were found to be associated with various measures of obesity. Of the 36 polymorphisms previously validated by genome-wide association studies (GWAS) elsewhere, only FTO and MC4R polymorphisms showed significant associations with obesity in black South Africans, Nigerians and Ghanaians. However, these data are insufficient to establish the true nature of genetic susceptibility to obesity in populations within Africa. There has been recent progress in describing the genetic architecture of obesity among populations within Africa. This effort needs to be sustained via GWAS studies.

Plasma urate in diabetes: relationship to glycaemia, glucose disposal, microvascular complications and the variations following oral glucose.

In order to provide further insights into the conflicting reports of associations between diabetes and uric acid metabolism, we studied 175 adult diabetic patients (56 IDDM, 119 NIDDM) and 114 matched control subjects. Plasma uric acid (PUA) concentrations were not significantly different between diabetic and control subjects, despite increased urinary urate in diabetic patients. There were no significant associations, in diabetic patients, between PUA and (i) type of diabetes, (ii) glycaemic control, (iii) retinopathy and (iv) proteinuria. Plasma urate did not correlate with the KG constant for glucose disposal rate during IVGTT, thus indicating that PUA may not be related to insulin action. In a separate study, PUA rose sharply, peaking at 30 min, and fell subsequently in both newly diagnosed NIDDM patients (n = 20) and subjects with impaired glucose tolerance (n = 15) in response to standard OGTT, in contrast to normal controls (n = 35) in whom PUA rose gradually to a peak at 120 min. Mean rise in PUA from baseline to peak was significant (P less than 0.05) in the diabetic group only. These differences in PUA response during an OGTT between subjects with abnormal glucose metabolism and normal controls may be a feature in the metabolic evolution of diabetes and need further investigation.

Erythrocyte and plasma magnesium status in Nigerians with diabetes mellitus.

Erythrocyte and fasting plasma magnesium were assayed by a dyebinding colorimetric method using the metallochromic dye, Calmagite, in 51 diabetic Nigerians and 25 controls. Erythrocyte magnesium concentrations were similar in the diabetics and the controls. Fasting plasma magnesium concentrations were significantly lower only in insulin-treated diabetics as compared to controls. No significant correlations were observed between fasting plasma glucose concentrations and either plasma or erythrocyte magnesium concentrations in the diabetic groups. Also, no significant correlation was found between erythrocyte magnesium and plasma magnesium concentrations. However, erythrocyte magnesium concentrations were directly related to age while plasma magnesium concentrations were directly related to duration of diabetes in all diabetics. Erythrocyte and plasma magnesium concentrations were not significantly affected by sex and degree of plasma glucose control. These results suggest that insulin-treated black African diabetics may develop hypomagnesaemia which is not associated with depletion of the erythrocyte content of magnesium.

Frequency, aetiology and outcome of hypernatraemia in hospitalised patients in Umtata, Transkei, South Africa.

OBJECTIVE: To study the frequency, aetiology and outcome of hypernatraemia in adult hospitalised patients. DESIGN: Retrospective hospital-based study of hypernatraemia using laboratory data to identify patients. OUTCOME MEASURES: Fluid intake, mortality, neurological signs and symptoms, serum sodium concentration. RESULT: The overall incidence of hypernatraemia was 1.4%. Among the 98 patients (mean age 44.6 years), head injury (30%), diabetes mellitus (22%), infection (13%) and gastro-intestinal disturbances (13%) were the principal aetiological conditions occurring in more than 75% of all hypernatraemic patients. Hypernatraemia was observed in both the young and the elderly. The overall mortality was high (56%), with significantly higher values in patients over the age of 44 years (66%) and those with serum sodium values greater than 165 mmol/L. Hospital-acquired hypernatraemia was more frequently (59%) observed than admission hypernatraemia (41%). Forty seven per cent of patients had no access to water, 31% were on diuretic therapy whilst solute diuresis was associated with hypernatraemia in 33%. Forty six per cent of patients were clinically dehydrated. Serum sodium levels normalised in more than half the patients (56%). Persistent hypernatraemia was associated with higher mortality. Though neurological signs and symptoms were observed in twelve per cent of patients, it was not associated with higher mortality. CONCLUSIONS: Hypernatraemia was observed in both the young and elderly and was associated with a high mortality. Hospital-acquired hypernatraemia was more frequently observed and was found to result from inadequate and inappropriate administration of fluids to patients with impaired thirst or restricted free water intake or both. Severe hypernatraemia appeared to be an indicator of poor prognosis.

Pilot study on plasma fatty acids in poorly controlled non insulin dependent diabetic Melanesians.

Different data have been reported with respect to the distribution of plasma and tissue fatty acids in patients with diabetes mellitus and some studies have suggested that severe diabetes is required to produce the fatty acid abnormalities observed in the diabetic rat. We studied the plasma fatty acid profile with particular attention to the omega 3 and 6 fatty acids in 14 non insulin dependent (NIDDM) diabetic Melanesians, majority of whom were poorly controlled (mean glycosylated haemoglobin levels of 12.8%), their mean age was 43.0 +/- 6.3 with disease duration of 5.2 +/- 4.8 years. Plasma fatty acids were estimated by gas chromatography (GC) using a flame ionisation detector (FID). Each diabetic was age and sex matched with a non diabetic, healthy control. Though the plasma concentrations of arachidonic (20:4, omega-6), eicosapentanoic (20:5 omega-3) and docosahaxaenoic (22:6 omega-3) acids were lower than in control subjects, these values were of no significant difference. Similarly, no significant differences were observed between the total plasma saturated fatty acids (palmitic and stearic acids) of diabetic and control subjects. The results of this pilot study suggest that poor metabolic control may not be associated with plasma fatty acid abnormalities in NIDDM patients.

Prevalence of some risk factors of coronary heart disease in a rural Nigerian population.

OBJECTIVE: To determine the prevalence of some risk factors of coronary heart disease (CHD) in a rural Nigerian population. DESIGN: Prospective cross-sectional study. SETTING: Three villages around Maiduguri in the north eastern part of Nigeria. SUBJECTS: Five hundred randomly selected subjects, consisting of 278 males and 222 females. INTERVENTION: Anthropometric parameters such as weight, height, body mass index and blood pressure were measured. Also fasting blood concentration of glucose, total cholesterol (Tc) and high density cholesterol (HDL-c) were measured. MAIN OUTCOME MEASURES: The various parameters were compared between males and females. RESULTS: Prevalence of hypercholesterolaemia was zero because no subjects had values greater than 5.2 mmol/1. Overall prevalence of obesity was 2%, with 1.2% in males and 3.2% in females. High blood pressure was observed in 15.2% of the subjects, with it being more among males (19.1%) than females (10.3%). Mean fasting blood glucose was significantly higher (p < 0.01) in females (6.2 mmol/1) than males (4.2 mmol/1). Prevalence of diabetes mellitus was 2.6% and being higher among females. CONCLUSION: Our results demonstrated lower prevalence of obesity and hypertension when compared with earlier results from the southern part of Nigeria, but showed an increase in the prevalence of diabetes mellitus. We therefore recommend that a survey of CHD risk factors should be carried out in different ethnic groups.

Diabetic retinopathy in Nigerians: relation to duration of diabetes, type of treatment and degree of control.

The results of a prospective study of the prevalence of diabetic retinopathy among Nigerian diabetics attending a Nigerian Teaching Hospital over a one and a half-year period are presented. Diabetics with mature cataracts whose fundi could not be visualised were excluded from the study. 15.1% of the 377 diabetic patients included in the study group had changes consistent with diabetic retinopathy. The prevalence was found to increase with increasing duration of disease, being 12.7%, 16.8% and 20.0% in patients with duration less than 5 years, between 5 and 10 years and greater than 10 years respectively. A considerably higher prevalence was also found in the insulin treated diabetics compared to the non insulin treated group (P less than 0.05). The degree of glycaemic control appeared to be poorer in the diabetics with retinopathy compared to those without, even though the differences between the mean fasting plasma glucose concentrations between the two groups did not reach statistical significance. Proteinuria was found to be significantly commoner in diabetics with retinopathy (P less than 0.025). It was concluded that diabetic retinopathy is on the increase among Nigerians and that efforts should be directed at evolving preventive measures and early identification of high risk patients.

Erythrocyte and plasma magnesium in sickle-cell anaemia.

Erythrocyte and plasma magnesium concentrations were measured in 168 subjects. Eighty three of the subjects were sickle-cell anaemia patients (sicklers) with haemoglobin genotype HbSS, and in the steady state; 30 were subjects who had the sickle-cell trait (HbAS), and 55 were subjects with the normal haemoglobin genotype HbAA. All the subjects were aged between 10 and 16 years. The sicklers had significantly lower erythrocyte (P less than 0.01) concentrations when compared with the normal subjects or subjects with the sickle-cell trait. Erythrocyte and plasma magnesium concentrations in subject with the sickle-cell trait were not significantly different from the corresponding values in the normal subjects. A significant negative correlation (r = -0.2661, P less than 0.02) was observed between erythrocyte magnesium and plasma magnesium in the sicklers only. However, magnesium concentrations in erythrocyte and plasma were not related to age, sex and physical stature in the three study groups. These results suggest that sickle-cell anaemia patients may be magnesium deficient.

Microalbuminuria in a clinic population of type 2 Melanesian diabetics: relationship to glycaemic control, blood pressure and duration of diabetes.

OBJECTIVE: To determine the prevalence of mcroalbuminuria in type 2 diabetes from Papua new Guinea and examine its association with glycaemic control, blood pressure and duration of diabetes. DESIGN: Prospective, type 2 Melanesian diabetics attending a diabetic clinic. SETTING: 800 bed teaching hospital in Port Moresby, Papua New Guinea. MAIN OUTCOME MEASURES: Microalbuminuria, glycaemic control, systolic and diastolic blood pressure, serum creatinine, duration of diabetes. RESULTS: Microalbuminuria was detected in 42% (34 males and 37 females of mean age 41 years) with significantly (p = 0.007) higher values being observed in males. Hypertension was present in 16.9% of diabetics. Both systolic and diastolic blood pressure measurements were significantly higher in diabetics with microalbuminuria. There were no significant differences in age, Body Mass Index (BMI), and glycaemic control in patients with or without microalbuminuria. On regression analysis, the presence of microalbuminuria was found to be independent of glycaemic control, duration of disease, (BMI), but influenced strongly by diastolic blood pressure (p = 0.002) and to a lesser degree by age (p = 0.043). CONCLUSION: There was a high prevalence of mcroalbuminuria, which was independent of glycaemic control, BMI and duration of disease. The presence of microalbuminuria was influenced by diastolic blood pressure and age. Patients with elevated creatinine levels were also found to be at risk.

The frequency, aetiology and outcome of severe hyponatraemia in adult hospitalised patients.

OBJECTIVE: To study the frequency, outcome and association with neurological signs and symptoms of severe hyponatraemia (< 120 mmol/l) in adult hospitalised patients. DESIGN: Retrospective study of severe hyponatraemia using laboratory data to identify patients. SETTING: 800 bed peri-urban hospital in the former homeland of Transkei. SUBJECTS: All adult inpatients from the medical and surgical wards with severe hyponatraemia during a 10 month period of which 18 cases records could not be traced and one was antefactual. MAIN OUTCOME MEASURES: Incidence of severe hyponatraemia, mortality, admission hyponatraemia, hospital acquired hyponatraemia, neurological symptoms and outcome. RESULTS: The overall incidence of severe hyponatraemia was 1.1%. Among the 58 patients (mean age 49.3 years), pulmonary tuberculosis (24%), Diabetes mellitus (19%) and renal failure (17.2%) were the principal aetiological conditions occurring in approximately 60% of hyponatraemic patients. A high mortality rate of 44.8% was observed which was probably associated with the severity of the underlying disease. 36.2% of patients had serum sodium levels of less than 115 mmol/l with a significantly (p < 0.05) higher mortality (62%) than those with values greater than 115 mmol/l (32%). Admission hyponatraemia (63.8%) was more frequent (p < 0.05) than hospital acquired hyponatraemia (36.2%); in the latter, hyponatraemia was more likely to normalise (p < 0.05). Neurological signs and symptoms developed in 17.2%, this being associated with a high mortality and lower mean serum sodium levels of 112 mmol/l respectively. Following therapy, serum sodium levels normalised in nearly half the patients. In three (5.2%) patients, the hyponatraemia worsened whilst another three became hypernatraemic. CONCLUSION: The incidence of severe hyponatraemia was lower than that observed in developed countries. It was associated with severe underlying disease and had a high mortality rate. Patients whose hyponatraemia did not normalise were more likely to have higher mortality.