Emerging trends in non-communicable disease mortality in South Africa, 1997 - 2010

Objectives. National trends in age-standardised death rates (ASDRs) for non communicable diseases (NCDs) in South Africa (SA) were identified between 1997 and 2010.Methods. As part of the second National Burden of Disease Study, vital registration data were used after validity checks, proportional redistribution of missing age, sex and population group, demographic adjustments for registration incompleteness, and identification of misclassified AIDS deaths. Garbage codes were redistributed proportionally to specified codes by age, sex and population group. ASDRs were calculated using mid-year population estimates and the World Health Organization world standard.Results. Of 594 071 deaths in 2010, 38.9% were due to NCDs (42.6% females). ASDRs were 287/100 000 for cardiovascular diseases (CVDs), 114/100 000 for cancers (malignant neoplasms), 58/100 000 for chronic respiratory conditions and 52/100 000 for diabetes mellitus. An overall annual decrease of 0.4% was observed resulting from declines in stroke, ischaemic heart disease, oesophageal and lung cancer, asthma and chronic respiratory disease, while increases were observed for diabetes mellitus, renal disease, endocrine and nutritional disorders, and breast and prostate cancers. Stroke was the leading NCD cause of death, accounting for 17.5% of total NCD deaths. Compared with those for whites, NCD mortality rates for other population groups were higher at 1.3 for black Africans, 1.4 for Indians and 1.4 for coloureds, but varied by condition.Conclusions. NCDs contribute to premature mortality in SA, threatening socioeconomic development. While NCD mortality rates have decreased slightly, it is necessary to strengthen prevention and healthcare provision and monitor emerging trends in cause-specific mortality to inform these strategies if the target of 2% annual decline is to be achieved

Estimating the burden of disease attributable to household air pollution from cooking with solid fuels in South Africa for 2000, 2006 and 2012

Background. Household air pollution (HAP) due to the use of solid fuels for cooking is a global problem with significant impacts on human health, especially in low- and middle-income countries. HAP remains problematic in South Africa (SA). While electrification rates have improved over the past two decades, many people still use solid fuels for cooking owing to energy poverty. Objectives. To estimate the disease burden attributable to HAP for cooking in SA over three time points: 2000, 2006 and 2012. Methods. Comparative risk assessment methodology was used. The proportion of South Africans exposed to HAP was assessed and assigned the estimated concentration of particulate matter with a diameter <2.5 μg/m3 (PM2.5) associated with HAP exposure. Health outcomes and relative risks associated with HAP exposure were identified. Population-attributable fractions and the attributable burden of disease due to HAP exposure (deaths, years of life lost, years lived with disability and disability-adjusted life years (DALYs)) for SA were calculated. Attributable burden was estimated for 2000, 2006 and 2012. For the year 2012, we estimated the attributable burden at provincial level. Results. An estimated 17.6% of the SA population was exposed to HAP in 2012. In 2012, HAP exposure was estimated to have caused 8 862 deaths (95% uncertainty interval (UI) 8 413 - 9 251) and 1.7% (95% UI 1.6% - 1.8%) of all deaths in SA, respectively. Loss of healthy life years comprised 208 816 DALYs (95% UI 195 648 - 221 007) and 1.0% of all DALYs (95% UI 0.95% - 1.0%) in 2012, respectively. Lower respiratory infections and cardiovascular disease contributed to the largest proportion of deaths and DALYs. HAP exposure due to cooking varied across provinces, and was highest in Limpopo (50.0%), Mpumalanga (27.4%) and KwaZulu-Natal (26.4%) provinces in 2012. Age standardised burden measures showed that these three provinces had the highest rates of death and DALY burden attributable to HAP. Conclusion. The burden of disease from HAP due to cooking in SA is of significant concern. Effective interventions supported by legislation and policy, together with awareness campaigns, are needed to ensure access to clean household fuels and improved cook stoves. Continued and enhanced efforts in this regard are required to ensure the burden of disease from HAP is curbed in SA

Estimating the changing burden of disease attributable to high sodium intake in South Africa for 2000, 2006 and 2012

Background. Elevated sodium consumption is associated with increased blood pressure, a major risk factor for cardiovascular and chronic kidney disease. Objectives. To quantify the deaths and disability-adjusted life years (DALYs) attributed to high sodium intake in persons aged ≥25 years in South Africa (SA) for 2000, 2006 and 2012. Methods. Comparative risk assessment (CRA) methodology was used and population attributable fractions (PAFs) of high sodium intake, mediated through high blood pressure (BP), for cardiovascular and chronic kidney disease were estimated. This was done by taking the difference between the PAF for elevated systolic BP (SBP) based on the estimated SBP level in the population and the PAF based on the estimated SBP that would result if sodium intake levels were reduced to the theoretical minimum risk exposure level (1 g/day) according to population group and hypertension categories. A meta-regression based on data from nine national surveys conducted between 1998 and 2017 was used to estimate the prevalence of hypertension by age, sex and population group. Relative risks identified from international literature were used and the difference in PAFs was applied to local burden estimates from the second South African National Burden of Disease Study. Age-standardised rates were calculated using World Health Organization (WHO) standard population weights. The attributable burden was also estimated for 2012 using an alternative target of 2 g/day proposed in the National Strategic Plan for the Prevention and Control of Non-communicable Diseases (NSP). Results. High sodium intake as mediated through high SBP was estimated to cause 8 071 (95% uncertainty interval (UI) 6 542 - 15 474) deaths in 2012, a drop from 9 574 (95% UI 8 158 - 16 526) in 2006 and 8 431 (95% UI 6 972 - 14 511) in 2000. In 2012, ischaemic heart disease caused the highest number of deaths in persons (n=1 832), followed by haemorrhagic stroke (n=1 771), ischaemic stroke (n=1 484) and then hypertensive heart disease (n=1 230). Ischaemic heart disease was the highest contributor to deaths for males (27%), whereas for females it was haemorrhagic stroke (23%). In 2012, 1.5% (95% UI 1.3 - 2.9) of total deaths and 0.7% (95% UI 0.6 - 1.2) of total DALYs were attributed to high sodium intake. If the NSP target of <2 g/day sodium intake had been achieved in 2012, ~2 943 deaths and 48 870 DALYs would have been averted. Conclusion. Despite a slight decreasing trend since 2006, high sodium intake mediated through raised BP accounted for a sizeable burden of disease in 2012. Realising SA’s target to reduce sodium intake remains a priority, and progress requires systematic monitoring and evaluation

Estimating the changing burden of disease attributable to high fasting plasma glucose in South Africa for 2000, 2006 and 2012

Background. Worldwide, higher-than-optimal fasting plasma glucose (FPG) is among the leading modifiable risk factors associated with all- cause mortality and disability-adjusted life years (DALYs) due to the direct sequelae of diabetes and the increased risk for cardiovascular and chronic kidney disease. Objectives. To report deaths and DALYs of health outcomes attributable to high FPG by age and sex for South Africa (SA) for 2000, 2006 and 2012. Methods. Comparative risk assessment methodology was used to estimate the burden attributable to high FPG. A meta-regression analysis was performed using data from national and small-area studies to estimate the population distribution of FPG and diabetes prevalence. Attributable fractions were calculated for selected health outcomes and applied to local burden estimates from the second South African National Burden of Disease Study (SANBD2). Age-standardised rates were calculated using World Health Organization world standard population weights. Results. We estimated a 5% increase in mean FPG from 5.31 (95% confidence interval (CI) 5.18 - 5.43) mmol/L to 5.57 (95% CI 5.41 - 5.72) mmol/L and a 75% increase in diabetes prevalence from 7.3% (95% CI 6.7 - 8.3) to 12.8% (95% CI 11.9 - 14.0) between 2000 and 2012. The age-standardised attributable death rate increased from 153.7 (95% CI 126.9 - 192.7) per 100 000 population in 2000 to 203.5 (95% CI 172.2 - 240.8) per 100 000 population in 2012, i.e. a 32.4% increase. During the same period, age-standardised attributable DALY rates increased by 43.8%, from 3 000 (95% CI 2 564 - 3 602) per 100 000 population in 2000 to 4 312 (95% CI 3 798 - 4 916) per 100 000 population in 2012. In each year, females had similar attributable death rates to males but higher DALY rates. A notable exception was tuberculosis, with an age-standardised attributable death rate in males double that in females in 2000 (14.3 v. 7.0 per 100 000 population) and 2.2 times higher in 2012 (18.4 v. 8.5 per 100 000 population). Similarly, attributable DALY rates were higher in males, 1.7 times higher in 2000 (323 v. 186 per 100 000 population) and 1.6 times higher in 2012 (502 v. 321 per 100 000 population). Between 2000 and 2012, the age-standardised death rate for chronic kidney disease increased by 98.3% (from 11.7 to 23.1 per 100 000 population) and the DALY rate increased by 116.9% (from 266 to 578 per 100 000 population). Conclusion. High FPG is emerging as a public health crisis, with an attributable burden doubling between 2000 and 2012. The consequences are costly in terms of quality of life, ability to earn an income, and the economic and emotional burden on individuals and their families. Urgent action is needed to curb the increase and reduce the burden associated with this risk factor. National data on FPG distribution are scant, and efforts are warranted to ensure adequate monitoring of the effectiveness of the interventions

Lead exposure in adult males in urban Transvaal Province, South Africa during the apartheid era

Human exposure to lead is a substantial public health hazard worldwide and is particularly problematic in the Republic of South Africa given the country’s late cessation of leaded petrol. Lead exposure is associated with a number of serious health issues and diseases including developmental and cognitive deficiency, hypertension and heart disease. Understanding the distribution of lifetime lead burden within a given population is critical for reducing exposure rates. Femoral bone from 101 deceased adult males living in urban Transvaal Province (now Gauteng Province), South Africa between 1960 and 1998 were analyzed for lead concentration by Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Of the 72 black and 29 white individuals sampled, chronic lead exposure was apparent in nearly all individuals. White males showed significantly higher median bone lead concentration (ME = 10.04 µg·g−1), than black males (ME = 3.80 µg·g−1) despite higher socioeconomic status. Bone lead concentration covaries significantly, though weakly, with individual age. There was no significant temporal trend in bone lead concentration. These results indicate that long-term low to moderate lead exposure is the historical norm among South African males. Unexpectedly, this research indicates that white males in the sample population were more highly exposed to lead

Estimating the changing disease burden attributable to smoking in South Africa for 2000, 2006 and 2012

Background. Ongoing quantification of the disease burden attributable to smoking is important to monitor and strengthen tobacco control policies. Objectives. To estimate the attributable burden due to smoking in South Africa for 2000, 2006 and 2012. Methods. We estimated attributable burden due to smoking for selected causes of death in South African (SA) adults aged ≥35 years for 2000, 2006 and 2012. We combined smoking prevalence results from 15 national surveys (1998 - 2017) and smoking impact ratios using national mortality rates. Relative risks between smoking and select causes of death were derived from local and international data. Results. Smoking prevalence declined from 25.0% in 1998 (40.5% in males, 10.9% in females) to 19.4% in 2012 (31.9% in males, 7.9% in females), but plateaued after 2010. In 2012 tobacco smoking caused an estimated 31 078 deaths (23 444 in males and 7 634 in females), accounting for 6.9% of total deaths of all ages (17.3% of deaths in adults aged ≥35 years), a 10.5% decline overall since 2000 (7% in males; 18% in females). Age-standardised mortality rates (and disability-adjusted life years (DALYs)) similarly declined in all population groups but remained high in the coloured population. Chronic obstructive pulmonary disease accounted for most tobacco-attributed deaths (6 373), followed by lung cancer (4 923), ischaemic heart disease (4 216), tuberculosis (2 326) and lower respiratory infections (1 950). The distribution of major causes of smoking-attributable deaths shows a middle- to high-income pattern in whites and Asians, and a middle- to low-income pattern in coloureds and black Africans. The role of infectious lung disease (TB and LRIs) has been underappreciated. These diseases comprised 21.0% of deaths among black Africans compared with only 4.3% among whites. It is concerning that smoking rates have plateaued since 2010. Conclusion. The gains achieved in reducing smoking prevalence in SA have been eroded since 2010. An increase in excise taxes is the most effective measure for reducing smoking prevalence. The advent of serious respiratory pandemics such as COVID-19 has increased the urgency of considering the role that smoking cessation/abstinence can play in the prevention of, and post-hospital recovery from, any condition