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Brain atrophy is correlated with risk of cognitive impairment, functional decline, and dementia. Despite a high infectious disease burden, Tsimane forager-horticulturists of Bolivia have the lowest prevalence of coronary atherosclerosis of any studied population and present few cardiovascular disease (CVD) risk factors despite a high burden of infections and therefore inflammation. This study (a) examines the statistical association between brain volume (BV) and age for Tsimane and (b) compares this association to that of 3 industrialized populations in the United States and Europe. This cohort-based panel study enrolled 746 participants aged 40-94 (396 males), from whom computed tomography (CT) head scans were acquired. BV and intracranial volume (ICV) were calculated from automatic head CT segmentations. The linear regression coefficient estimate β^T of the Tsimane (T), describing the relationship between age (predictor) and BV (response, as a percentage of ICV), was calculated for the pooled sample (including both sexes) and for each sex. β^T was compared to the corresponding regression coefficient estimate β^R of samples from the industrialized reference (R) countries. For all comparisons, the null hypothesis β T = β R was rejected both for the combined samples of males and females, as well as separately for each sex. Our results indicate that the Tsimane exhibit a significantly slower decrease in BV with age than populations in the United States and Europe. Such reduced rates of BV decrease, together with a subsistence lifestyle and low CVD risk, may protect brain health despite considerable chronic inflammation related to infectious burden.

This article, published in the European Heart Journal, presents the findings of the HORUS study, which aimed to investigate the presence of atherosclerosis in ancient mummified humans. The study analyzed whole body CT scans of mummies from seven different cultures, including Egyptian, Peruvian, Bolivian, Unangan/Aleutian Islander, Greenlandic Inuit, ancestral Puebloan, and Middle-Ages Gobi Desert pastoralists. The results showed that atherosclerosis was present in all cultures except for one Indigenous Australian mummy. The study suggests that atherosclerosis has been a part of human populations for thousands of years and supports the existence of an innate human predisposition to the disease. [Extracted from the article]

Background In industrialized populations, low male testosterone is associated with higher rates of cardiovascular mortality. However, coronary risk factors like obesity impact both testosterone and cardiovascular outcomes. Here, we assess the role of endogenous testosterone on coronary artery calcium in an active subsistence population with relatively low testosterone levels, low cardiovascular risk and low coronary artery calcium scores. Methodology In this cross-sectional community-based study, 719 Tsimane forager-horticulturalists in the Bolivian Amazon aged 40+ years underwent computed tomography (49.8% male, mean age 57.6 years). Results Coronary artery calcium levels were low; 84.5% had no coronary artery calcium. Zero-inflated negative binomial models found testosterone was positively associated with coronary artery calcium for the full sample (Incidence Rate Ratio [IRR] = 1.477, 95% Confidence Interval [CI] 1.001–2.170, P = 0.031), and in a male-only subset (IRR = 1.532, 95% CI 0.993–2.360, P = 0.053). Testosterone was also positively associated with clinically relevant coronary atherosclerosis (calcium >100 Agatston units) in the full sample (Odds Ratio [OR] = 1.984, 95% CI 1.202–3.275, P = 0.007) and when limited to male-only sample (OR = 2.032, 95% CI 1.118–4.816, P = 0.024). Individuals with coronary artery calcium >100 had 20% higher levels of testosterone than those with calcium <100 (t = –3.201, P = 0.007). Conclusions and Implications Among Tsimane, testosterone is positively associated with coronary artery calcium despite generally low normal testosterone levels, minimal atherosclerosis and rare cardiovascular disease (CVD) events. Associations between low testosterone and CVD events in industrialized populations are likely confounded by obesity and other lifestyle factors. [ABSTRACT FROM AUTHOR]

To correlate atherosclerosis (Ath) and osteoarthritis (OA) in mummies from ancient Egypt. Whole-body CT examinations of 23 mummies from the Ägyptisches Museum und Papyrussammlung, Berlin, Germany, and 22 mummies from the Museo Egizio, Turin, Italy. Ath was assessed in five anatomical regions by means of preserved arterial calcifications. OA was assessed using the Kellgren and Lawrence (1957) classification. Statistical analysis revealed no correlation between Ath and total OA. A significant association was found for Ath and the upper limb group for OA grade >1 and for Ath and the lower limb group, consisting mainly of the hip and knee, for OA grade >2 OA. The association of Ath and advanced OA of the hip and knee is comparable in prevalence to those reported in recent clinical studies, despite the low life expectancy and the different environment and lifestyle of the ancient Egyptians. This is the first study to correlate findings of Ath and OA in ancient Egypt statistically. The diseases of Ath and OA are common ailments with enormous and increasing impacts on public health. The large number of cardiovascular diseases was indicated only by arterial calcifications that resisted the post-mortem changes of the mummification process. Also, the assessed OA was on radiological OA. Genomic studies of ancient Egyptian mummies may reveal genetic risk factors for Ath and OA that could be shared in ancient and modern populations. [ABSTRACT FROM AUTHOR]