Pedro Ordunez

Population-wide weight loss and regain in relation to diabetes burden and cardiovascular mortality in Cuba 1980-2010: repeated cross sectional surveys and ecological comparison of secular trends

Objective To evaluate the associations between population-wide loss and gain in weight with diabetes prevalence, incidence, and mortality, as well as cardiovascular and cancer mortality trends, in Cuba over a 30 year interval. Design Repeated cross sectional surveys and ecological comparison of secular trends. Setting Cuba and the province of Cienfuegos, from 1980 to 2010. Participants Measurements in Cienfuegos included a representative sample of 1657, 1351, 1667, and 1492 adults in 1991, 1995, 2001, and 2010, respectively. National surveys included a representative sample of 14 304, 22 851, and 8031 participants in 1995, 2001, and 2010, respectively. Main outcome measures Changes in smoking, daily energy intake, physical activity, and body weight were tracked from 1980 to 2010 using national and regional surveys. Data for diabetes prevalence and incidence were obtained from national population based registries. Mortality trends were modelled using national vital statistics. Results Rapid declines in diabetes and heart disease accompanied an average population-wide loss of 5.5 kg in weight, driven by an economic crisis in the mid-1990s. A rebound in population weight followed in 1995 (33.5% prevalence of overweight and obesity) and exceeded pre-crisis levels by 2010 (52.9% prevalence). The population-wide increase in weight was immediately followed by a 116% increase in diabetes prevalence and 140% increase in diabetes incidence. Six years into the weight rebound phase, diabetes mortality increased by 49% (from 9.3 deaths per 10 000 people in 2002 to 13.9 deaths per 10 000 people in 2010). A deceleration in the rate of decline in mortality from coronary heart disease was also observed. Conclusions In relation to the Cuban experience in 1980-2010, there is an association at the population level between weight reduction and death from diabetes and cardiovascular disease; the opposite effect on the diabetes and cardiovascular burden was seen on population-wide weight gain.

Prevalence estimates for hypertension in Latin America and the Caribbean: are they useful for surveillance?

OBJECTIVE To apply a recently proposed model and assessment tool created by the authors for critically evaluating the data available on the prevalence of hypertension in LAC and assessing their usefulness for surveillance. METHODS A bibliographic search to identify all publications that estimated the prevalence of hypertension was performed. Each of the papers located was assessed using a critical appraisal tool. RESULTS Of the 58 studies published between 1966 and 2000, only 28 of them (48%) met the critical threshold to be considered useful for surveillance purposes. The distribution of the 28 studies in terms of their usefulness for surveillance was as follows: minimally useful, 16 studies; useful, 8 studies; and very useful, 4 studies. Several methodological shortcomings were identified, from inadequate sampling procedures and sample size to the poor quality of the primary data for planning purposes. DISCUSSION Published studies on the prevalence of hypertension in Latin America and the Caribbean have, as a whole, limited usefulness for surveillance activities.

Cardiovascular Disease and Associated Risk Factors in Cuba: Prospects for Prevention and Control

OBJECTIVES An adequate description of the trends in cardiovascular disease (CVD) is not available for most of the developing world. Cuba provides an important exception, and we sought to use available data to offer insights into the changing patterns of CVD there. METHODS We reviewed Cuban public health statistics, surveys, and reports of health services. RESULTS CVD has been the leading cause of death since 1970. A 45% reduction in heart disease deaths was observed from 1970 to 2002; the decline in stroke was more limited. There are moderate prevalences of all major risk factors. CONCLUSIONS The Cuban medical care system has responded vigorously to the challenge of CVD; levels of control of hypertension are the highest in the world. Nonindustrialized countries can decisively control CVD.

Cardiovascular disease mortality in the Americas: current trends and disparities

Objective To describe the current situation and trends in mortality due to cardiovascular disease (CVD) in the Americas and explore their association with economic indicators. Design and Setting This time series study analysed mortality data from 21 countries in the region of the Americas from 2000 to the latest available year. Main Outcomes Measures Age-adjusted death rates, annual variation in death rates. Regression analysis was used to estimate the annual variation and the association between age-adjusted rates and country income. Results Currently, CVD comprised 33.7% of all deaths in the Americas. Rates were higher in Guyana (292/100 000), Trinidad and Tobago (289/100 000) and Venezuela (246/100 000), and lower in Canada (108/100 000), Puerto Rico (121/100 000) and Chile (125/100 000). Male rates were higher than female rates in all countries. The trend analysis showed that CVD death rates in the Americas declined −19% overall (−20% among women and −18% among men). Most countries had a significant annual decline, except Guatemala, Guyana, Suriname, Paraguay and Panama. The largest annual declines were observed in Canada (−4.8%), the USA (−3.9%) and Puerto Rico (−3.6%). Minor declines were in Mexico (−0.8%) and Cuba (−1.1%). Compared with high-income countries the difference between the median of death rates in lower middle-income countries was 56.7% higher and between upper middle-income countries was 20.6% higher. Conclusions CVD death rates have been decreasing in most countries in the Americas. Considerable disparities still remain in the current rates and trends.

Obesity reduction and its possible consequences: What can we learn from Cuba's Special Period?

In a recent issue of the American Journal of Epidemiology ,[1][1] we described the relation between sustained population-wide weight loss and a decline in all-cause mortality and in the rates of death from diabetes mellitus and cardiovascular disease in Cuba. The widespread weight loss resulted from

Risk factors associated with uncontrolled hypertension: findings from the baseline CARMEN survey in Cienfuegos, Cuba.

Objectives Identifying methods to improve pharmacologic control of elevated blood pressure remains the most urgent challenge in clinical research on hypertension. The probability of having inadequate control varies widely in the population and better understanding of the factors responsible could help to focus treatment strategies. Methods A population-based community survey of 1475 persons aged 25–74 years, in Cienfuegos, Cuba, was used to identify these factors in a low-resource setting. Results While half of women with hypertension were controlled, only one-third of men were receiving successful treatment. Gender differences were not seen, however, among those currently taking medications. The largest burden of hypertension in absolute terms was concentrated in the age range 45–64, emphasizing the heavy burden of uncontrolled high blood pressure that falls on middle-aged men. Race-ethnicity was not a determinant of treatment and control status, nor was inability to obtain medication. Conclusions These findings largely confirm the pattern observed in industrialized countries and demonstrate the near-universal challenge confronting primary-care systems in physician-based control of cardiovascular risk factors.

The epidemic of chronic kidney disease in Central America

Immediate and coordinated action is needed to address the epidemic of chronic kidney disease sweeping across Central America. The disorder, known as CKDnT, is not related to traditional causes such as hypertension and diabetes, and mainly aff ects young male agricultural workers, the highest mortality being in El Salvador and Nicaragua (fi gure). However, CKDnT also aff ects women and non-agricultural workers living in farming communities. Mortality estimates from the Pan American Health Organization (PAHO) show that chronic kidney disease coded as N18 in WHO’s International Classifi cation of Diseases revision 10—a proxy for CKDnT—in men younger than 60 years has been responsible for thousands of deaths in the past decade in Central America. CKDnT is characterised by a tubulointerstitial nephropathy with low-grade proteinuria, which has a long subclinical period that tends to progress to end-stage renal disease in a short period of time. The scarcity of coverage and access to health services might contribute to the clinical course and high mortality rates of CKDnT. Health authorities, for example in El Salvador, responded to this poor coverage by increasing access to health services; however, the large number of patients and absence of adequate infrastructure and trained personnel led to overloaded hospitals. Similar epidemiological and clinical patterns of CKDnT have been reported in other countries, such as Sri Lanka. Causes of the CKDnT epidemic are not clear, although a consensus exists among researchers on its multifactorial character and relation to social, environmental, and economic determinants. Most commonly postulated causes include exposure to pesticides, heat stress with recurrent dehydration, and an excessive intake of high-sugar drinks. Exposure to heavy metals, use of non-steroidal anti-infl ammatory drugs and alcohol, and infectious diseases have similarly been postulated as causes for the CKDnT epidemic. Research to identify determinants of the epidemic is necessary, but the moral duty to address an epidemic cannot be postponed until its causes are identifi ed. A coordinated response from the public health sector and other related sectors is urgently needed. In addition to health services required to treat aff ected people, public health bodies need to consider environmental and occupational health measures. The two main hypotheses for the high incidence and excess mortality—ie, the use of pesticides and heat stress along with dehydration—are strongly related to the absence of a regulatory system to control agrochemical use and the poor compliance with rules and standards to protect the labour force’s health. Almost all Central American countries are signatories to the Stockholm Convention on Persistent Organic Pollutants and the Rotterdam Convention on Prior Informed Consent. Compliance, however, is far from

Chronic interstitial nephritis in agricultural communities: a worldwide epidemic with social, occupational and environmental determinants

Abstract Increase in the prevalence of chronic kidney disease (CKD) is observed in Central America, Sri Lanka and other tropical countries. It is named chronic interstitial nephritis in agricultural communities (CINAC). CINAC is defined as a form of CKD that affects mainly young men, occasionally women. Its aetiology is not linked to diabetes, hypertension, glomerulopathies or other known causes. CINAC patients live and work in poor agricultural communities located in CINAC endemic areas with a hot tropical climate, and are exposed to toxic agrochemicals through work, by ingestion of contaminated food and water, or by inhalation. The disease is characterized by low or absent proteinuria, small kidneys with irregular contours in CKD stages 3‐4 presenting tubulo‐interstitial lesions and glomerulosclerosis at renal biopsy. Although the aetiology of CINAC is unclear, it appears to be multifactorial. Two hypotheses emphasizing different primary triggers have been proposed: one related to toxic exposures in the agricultural communities, the other related to heat stress with repeated episodes of dehydration heath stress and dehydration. Existing evidence supports occupational and environmental toxins as the primary trigger. The heat stress and dehydration hypothesis, however, cannot explain: why the incidence of CINAC went up along with increasing mechanization of paddy farming in the 1990s; the non‐existence of CINAC in hotter northern Sri Lanka, Cuba and Myanmar where agrochemicals are sparsely used; the mosaic geographical pattern in CINAC endemic areas; the presence of CINAC among women, children and adolescents who are not exposed to the harsh working conditions; and the observed extra renal manifestations of CINAC. This indicates that heat stress and dehydration may be a contributory or even a necessary risk factor, but which is not able to cause CINAC by itself.

Chronic Kidney Disease Epidemic in Central America: Urgent Public Health Action Is Needed amid Causal Uncertainty

The 52nd Directing Council of the Pan American Health Organization (PAHO), in response to a call for action of the Minister of Health of El Salvador, recognized chronic kidney disease from nontraditional causes (CKDnT) affecting agricultural communities in Central America as a serious public health problem that requires urgent, effective, and concerted multisectoral action [1]. Most Central American countries do not have surveillance systems capable of detecting chronic kidney disease (CKD). However, many reports [2]–[4] and data from PAHO show the epidemiological magnitude of the disease. A proxy for CKDnT mortality, the age standardized mortality rate due to chronic kidney disease—coded as N18 (CKD-N18) by the 2010 International Classification of Diseases—is notably higher for men and women in Nicaragua and El Salvador compared to other countries in the region and has been since at least 2000 (http://www.paho.org/hq/index.php?option=com_content&view=article&id=9402). CKD-N18 data also show disproportionate mortality from the disease in males compared to females (Figure 1). Mortality due to CKD in El Salvador and Nicaragua exhibited a pattern of excess mortality in young adults (Figure 2), which is consistent with many other clinical and epidemiological reports [2]–[4]. Figure 1 Chronic kidney disease (N18; International Classification of Diseases, tenth revision [ICD-10]) age-standardized mortality rate, selected countries, 2000–2009. Figure 2 Chronic kidney disease (N18, ICD-10) age-specific mortality rate, selected countries, around 2008. CKDnT has been largely reported in some clustered farming communities traditionally burdened by socioeconomic disadvantages from northern Nicaragua [2], the Pacific coast of El Salvador [3], and other countries such as Costa Rica, Guatemala, Honduras, and the south of Mexico [4]. The disease affects mostly young adult male agricultural workers, e.g., sugarcane cutters. CKDnT has also been described in agricultural workers in Sri Lanka and India [5]–[6]. Studies reveal that patients affected by CKDnT show a clinical and pathologic pattern of a tubule-interstitial disease [7]–[8], which seems to progress to end-stage renal disease in a relatively short time. This clinical pattern explains at least in part the high burden imposed on the affected countries for the delivery of health services. For example, a 50% increase in hospitalizations for CKD from 2005 to 2012 was reported in El Salvador, making CKD the leading cause of death in El Salvadors main hospital [1]. CKDnT is a chronic and multifactorial condition that has been neglected for quite some time. The causes of this epidemic have not been elucidated yet. Several potential etiological factors have been considered [7]. Given the diseases higher prevalence in agricultural communities and its clinical and epidemiological characteristics, which are similar to CKDnT in Sri Lanka [5], it is reasonable to draw attention to two interdependent factors: the misuse of agrochemicals and the working conditions of the labor force. The misuse of pesticides has been widespread in Central America for a long time [9]. This region imported 33 million kg of active ingredient per year with an increase of 33% during 2000–2004. From a total of 403 pesticides (13 of which constitute 77% of the total pesticides that were imported), 22% were highly/extremely acutely toxic, 33% were moderately/severely irritating or sensitizing, and 30% had multiple chronic toxicities. Out of 41 banned or highly regulated pesticides as per international treaties, 16 were imported to Central America, four of which are among the 13 most imported pesticides [10]. Although the specific mechanisms to explain the nephrotoxicity of some pesticides are still under investigation, the nephrotoxicity of several of them is already known [11], [12]. Harsh working conditions, especially regular exposure to very hot temperatures and extreme physical effort, lead to heat stress and dehydration. Along with exposure to pesticides, these seem to play an important role in the occurrence of the disease, particularly among sugarcane cutters [13]. The weakness of regulatory systems [10], along with the agriculture dependency of local economies [14] and cultural agricultural practices [9], contribute to poor compliance with international safety and health standards for the use of agrochemicals and for occupational hygiene. Many questions related to these potential causative agents remain unanswered. For example, why is there such an important difference in the distribution of CKD between countries? Are there differences in the agricultural practices and work processes in areas with the same climatic characteristics and devoted to the same type of plantations (e.g., sugarcane)? Which types of agrochemicals have been used in the affected areas? How do we explain cases in nonsugarcane cutters, as well as in women? Other hypothesized causal agents merit further investigation. Nonsteroidal anti-inflammatory drugs, alcohol, and sugary beverage consumption have been associated with the disease [7], but their role remains controversial in current scientific evidence. The potential role of heavy metals and contamination of fertilizer has not been investigated in depth in the region and deserves more research. It has been argued that infectious diseases such as leptospirosis and dengue, which are prevalent in the region, could also play a role in the CKDnT epidemic [7]. However, these hypothesis have not been supported by evidence. Indeed, the human transmission of the West Nile virus, which has been associated with CKD [15], has not been documented in Central America until now. A CKDnT regional research agenda is imperative not only to drive efforts to determine the epidemics causative agents but also to bridge the gap between research and public health interventions. However, much-needed research must not delay action to address CKDnT. The resolution on CKDnT in Central America approved by PAHOs Directing Council [1] commits to coordinated and evidence-informed action to implement public policies, programs, and regulatory mechanisms to improve the social, environmental, occupational, and economic conditions of the affected communities and to strengthen surveillance and CKD-relevant health services. The resolution of PAHO [1] also highlighted the relevance of multisectorial actions outside of the health sector—for instance, agriculture, trade, environment, occupational safety, affected communities, academia, and civil society, among others—to coordinate efforts, mobilize resources, prioritize the sustainability of actions to promote evidence-based public policies, and to reach the high level of commitment to reduce environmental risk factors to mitigate, on an urgent basis, the health, social, and economic consequences of this disease. An effective and urgent response to address and ultimately stop the epidemic is a moral duty not only for Central America but for the whole Pan American community.

Usefulness for surveillance of hypertension prevalence studies in Latin America and the Caribbean: the past 10 years

OBJECTIVE To compare the usefulness for surveillance of the peer-reviewed literature on the prevalence of hypertension in Latin America and the Caribbean published from 2001 to 2010 with a previous study of the published literature from 1962 to 2000. METHODS A bibliographic search was conducted of publications from 2001 to 2010 that examined the prevalence of hypertension using MEDLINE and LILACS databases. The methodology of each paper was evaluated with the same critical appraisal tool used in the previous study. RESULTS A total of 81 papers were published from 2001 to 2010 on the prevalence of hypertension in Latin America and the Caribbean. Only 24 of these studies met the minimum methodologic criteria for evaluation. While the total number of studies published in the past 10 years exceeds the number published from 1962 to 2000, the percentage of studies that met the minimum methodologic criteria has not substantially increased. In addition to major methodologic shortcomings, less than 46% of the published studies reported rates of awareness, treatment, and control of hypertension. The hypertension prevalence estimates from the peer-reviewed literature range from 7% to 49%. These studies were primarily done in urban centers and are not evenly distributed throughout the region. CONCLUSIONS The quality and geographic distribution of the published literature on the prevalence of hypertension in Latin America and the Caribbean are inadequate. Research resources and efforts should be directed in the future toward closing this gap.