Frequent left ventricular hypertrophy independent of blood pressure in 1851 pre-western Inuit.

BACKGROUND: Elevated blood pressure is a risk factor for cardiovascular disease and may be detected by left ventricular hypertrophy (LVH) in electrocardiogram (ECG). Pre-western Inuit had frequent signs of LVH in ECG predominantly in the 3rd decade while a low occurrence of ischemic heart disease. METHODS: We evaluated the association between blood pressures and ECG signs of LVH, cardiac auscultation, and symptoms related to heart disease in the recently recovered data from the survey of 1851 Inuit conducted in 1962-1964 in East Greenland. RESULTS: The participation rate was 97%. Among the 812 Inuit aged 18 years or above blood pressure was unaltered until the age of 39 years (systolic, p=76; diastolic, p=0.36) and increased subsequently (both, p<0.001). Systolic blood pressure >140 mmHg was more frequent when aged >40 years (p<0.001) and diastolic blood pressure >90 mmHg was more common in men (p<0.001) and in men and women aged >40 years (p<0.001). ECG signs of LVH were more frequent in men (p<0.01) but the occurrence decreased from the age of 40 years (p<0.01), and were not influenced by systolic (p=0.97), diastolic (p=0.87) or pulse pressure (p=0.69). CONCLUSIONS: Blood pressure rose only after the age of 40 years in pre-western Inuit. Left ventricular hypertrophy peaked among 30-year olds and was independent of elevated blood pressure. It may be speculated that the common left ventricular hypertrophy was due to marked physical activity that contributed to the low occurrence of ischemic heart disease among pre-western Inuit.

Endocarditis in Greenland with special reference to endocarditis caused by Streptococcus pneumoniae.

OBJECTIVES: The aim of this retrospective study was to determine the incidence and outcome of infectious endocarditis in Greenland with an emphasis on pneumococcal endocarditis. STUDY DESIGN: Retrospective, non-interventional study. METHODS: Review of files and medical history of all patients with infectious endocarditis from the Patient Registry in Greenland in the 11-year period 1995-2005. RESULTS: There were 25 cases of endocarditis, giving an incidence rate of 4.0/100,000 per year. Twenty-four percent of these cases were caused by Streptoccous pneumonia, which is significantly more frequent than in studies on Caucasian populations, where pneumococcal infection was seen in 1-3% of endocarditis cases. The overall mortality rate was 12%. Pneumococcal endocarditis (PE) had the clinical characteristics of fulminant disease with frequent heart failure, complications and need for surgery. Among cases with PE, 67% needed acute valve replacement and the mortality rate was 33%. CONCLUSIONS: The high incidence rate, clinical characteristics and grave prognosis of PE are consistent with another study of an Inuit population in Alaska.

Low occurrence of ischemic heart disease among Inuit around 1963 suggested from ECG among 1851 East Greenland Inuit.

BACKGROUND: The prevalence of coronary heart disease among Greenland Inuit today is similar to that of western populations. The cardiovascular risk profile among Inuit has changed over the past four decades with the introduction of a western life style. An unaltered prevalence of coronary heart disease has been proposed, but no pre-westernisation data exist. AIM: To describe pre-westernisation prevalence of coronary heart disease among East Greenland Inuit. DESIGN: A population study of 1851 Inuit living in East Greenland was conducted in 1962-1964. It included ECG, cardiac auscultation and recording of symptoms. ECGs were evaluated for ischemic signs, arrhythmia, hypertrophy, and conduction abnormalities. RESULTS: The participation rate was 97%. A12-lead ECG was performed in 181 adults, including 65% of men aged 40 years and above. Hypertrophy was seen in 15% and peaked in 30-39 year olds. Pathological conduction disturbances were seen in 4% and 1% had ischemic signs. The age-standardised prevalence of ischemic ECG findings was 5.5%. Abnormal ECG findings did not correlate with pathologic findings on cardiac auscultation or symptoms related to heart disease. CONCLUSIONS: Hypertrophy peaked among 30 years olds. Ischemic ECG findings were present in East Greenland Inuit before westernisation, the prevalence clearly lower than today.

High prevalence of markers of coronary heart disease among Greenland Inuit.

OBJECTIVE: It is a common notion that coronary heart disease (CHD) is rare among the Inuit, possibly due to a high intake of omega-3-fatty acids. The scientific evidence for this is weak and to some extent based on uncertain mortality statistic. The aim of this study was to assess the prevalence of markers of CHD among Greenland Inuit, and to study associations between markers of CHD and behavioral and biological variables. DESIGN: We studied prevalence of angina pectoris (AP), self-reported myocardial infarction (MI), and ECG defined MI and ischaemia in a population survey among 1316 Inuit living in Greenland. Blood tests were supplemented by structured interviews, anthropometry, and measurements of blood pressure, and the participants received an oral glucose tolerance test. RESULTS: The prevalence of symptomatic CHD (AP, self-reported MI) was 7.3% among men and 6.9% among women, and 12.2% and 13.4% of men and women had ischaemic ECG changes. The overall prevalence of CHD (AP+self-reported MI+ECG defined MI) was 10.8% in men and 10.2% in women. The highest prevalence was observed in the least westernized areas in Greenland. Physical inactivity, low education, dyslipidemia, hypertension and diabetes were associated with CHD. CONCLUSION: The prevalence of markers of CHD was not different from that in Western populations. The Inuit is a population undergoing rapid social and health transitions, with the emergence of cardiovascular risk factors, and there is a need for critical rethinking of cardiovascular epidemiology in this population.

Hyperinsulinaemia is associated with increased long-term mortality following acute myocardial infarction in non-diabetic patients.

AIMS: To study the impact of disturbances in glucose metabolism on total mortality in non-diabetic patients with acute myocardial infarction. METHODS AND RESULTS: Four hundred and ninety four patients with a verified myocardial infarction and no history of diabetes were studied. The study population comprised a subgroup of patients screened for participation in the Trandolapril Cardiac Evaluation (TRACE) study. At baseline, fasting insulin, fasting glucose, glycosylated haemoglobin (HbA1c), and urinary albumin excretion were measured. Survival status was determined after 6-8 years. Patients with hyperinsulinaemia were more obese and more frequently suffered from hypertension, previous myocardial infarction and congestive heart failure. In a univariate regression analysis, values in the upper quartile of insulin, glucose, HbA1c, and urinary albumin were associated with an excess mortality risk (RR=1.8 (1.2-2.7), p=0.002; RR=1.6 (1.2-2.1), p=0.001; RR= 1.9 (1.3-2.9), p=0.001; RR=1.6 (1.2-2.1), p=0.02 respectively). However, only a high insulin level remained significant in a multivariable analysis (RR=1.54 (1.03-2.31), p=0.04) including baseline variables, left ventricular systolic function and in-hospital complications. CONCLUSIONS: High fasting plasma insulin is an independent risk factor of all-cause mortality in non-diabetic patients with acute myocardial infarction. This justifies future intervention studies aiming at reducing insulin resistance and using fasting insulin as the target variable.