Ultrasonography of the Carotid Artery to Measure the IMT

<div><p>This figure provides a framework for understanding the multiple, quantitative calculations undertaken for each patient's carotid ultrasound scan. Two images of carotid artery without plaques (left) and two with plaques (right) are shown at the top. ROI indicates the region of interest in which thickness measurements are made. These were obtained from a single patient. Schematics for each image are provided below the video images. The grey lines indicate the measured IMT within the defined region of interest. Regarding the plaques (PL₁ and PL₂), M indicates maximum plaque thickness, and L indicates minimum lumen diameter at the site of maximum plaque thickness. Percent diameter stenosis is calculated as [M/(M + L)] × 100%. The graph (bottom) indicates length in millimeters on the x-axis and thickness in millimeters on the y-axis. The areas from the far wall of the left (L) and right (R) common carotid arteries are measured in all patients. AIMT designates the average IMT derived from the left and right measurements. PL₁ and PL₂ are the lesion lengths of the respective plaques, and M₁ and M₂ are the respective maximal thicknesses. APT₁ and APT₂ designate the respective average lesion thicknesses for each plaque. The total area is given by the sum of all the areas shown on the graph in units of square millimeters. The average total thickness (ATT) is given by the total area divided by the total length shown on the x-axis. PL_n on the x-axis is intended to indicate that the calculations are undertaken using these concepts, irrespective of the number of plaques identified in a given study.</p> <p>(Figure from [<a href="http://www.plosmedicine.org/article/info:doi/10.1371/journal.pmed.0020098#pmed-0020098-b28" target="_blank">28</a>] with permission of all four authors.)</p></div

The High Risk Versus the Population Approach to Prevention

<p>(Figure: John Emberson)</p

Dietary Salt Reduction and Cardiovascular Disease Rates in India: A Mathematical Model

<div><h3>Background</h3><p>Reducing salt intake has been proposed to prevent cardiovascular disease in India. We sought to determine whether salt reductions would be beneficial or feasible, given the worry that unrealistically large reductions would be required, worsening iodine deficiency and benefiting only urban subpopulations.</p> <h3>Methods and Results</h3><p>Future myocardial infarctions (MI) and strokes in India were predicted with a Markov model simulating men and women aged 40 to 69 in both urban and rural locations, incorporating the risk reduction from lower salt intake. If salt intake does not change, we expect ∼8.3 million MIs (95% CI: 6.9–9.6 million), 830,000 strokes (690,000–960,000) and 2.0 million associated deaths (1.5–2.4 million) per year among Indian adults aged 40 to 69 over the next three decades. Reducing intake by 3 g/day over 30 years (−0.1 g/year, 25% reduction) would reduce annual MIs by 350,000 (a 4.6% reduction; 95% CI: 320,000–380,000), strokes by 48,000 (−6.5%; 13,000–83,000) and deaths by 81,000 (−4.9%; 59,000–100,000) among this group. The largest decline in MIs would be among younger urban men, but the greatest number of averted strokes would be among rural men, and nearly one-third of averted strokes and one-fifth of averted MIs would be among rural women. Only under a highly pessimistic scenario would iodine deficiency increase (by <0.0001%, ∼1600 persons), since inadequate iodized salt access—not low intake of iodized salt—is the major cause of deficiency and would be unaffected by dietary salt reduction.</p> <h3>Conclusions</h3><p>Modest reductions in salt intake could substantially reduce cardiovascular disease throughout India.</p> </div

Model diagram.

<p>Health states are further divided into age-, gender- and location-specific (urban and rural) submodels. Deaths from non-cardiovascular events are calculated from each compartment of the model at each time point in the simulation (not drawn). The transition probabilities between health states in the model are detailed in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0044037#pone.0044037.s008" target="_blank">Tables S1</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0044037#pone.0044037.s009" target="_blank">S2</a> and <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0044037#pone.0044037.s010" target="_blank">S3</a>. Dietary salt reduction in the model lowers the risk of incident and recurrent myocardial infarction and stroke events. MI: myocardial infarction.</p

Determinants of the level of population exposure to unhealthy foods, beverages, and tobacco, 44 LMICs (GDP

<p><i>Notes:</i> Robust-clustered errors in parentheses to reflect non-independence of country sampling.</p>*<p><i>p</i><0.05,</p>**<p><i>p</i><0.01,</p>***<p><i>p</i><0.001.</p

Associations of tobacco, alcohol, soft drink and processed food markets, 80 countries, 2010.

<p>Associations of tobacco, alcohol, soft drink and processed food markets, 80 countries, 2010.</p

Sensitivity analyses.

<p>Projected Estimates of Reductions in Cardiovascular Disease from a Dietary Salt Reduction Target of 3 g/day achieved over 30 years (via a linear reduction in intake of 0.1 g/year), in the Main Simulation and According to Various Assumptions about Differential Salt Sensitivity and Blood Pressure Reduction Benefits in the Sensitivity Analyses. MI and stroke incidence includes both new cases and recurrent events.</p>*<p>Cardiovascular benefit of lowering blood pressure was equivalent to two-thirds of the benefit for a person whose native blood pressure was at that lower blood pressure level <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0044037#pone.0044037-Law1" target="_blank">[42]</a>.</p>**<p>While the baseline simulation implements the results of a meta-analysis that does not reveal greater salt sensitivity among the elderly <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0044037#pone.0044037-He2" target="_blank">[27]</a>, we also simulated the case in which each gram reduction in salt intake leads to a greater reduction in blood pressure among older cohorts, as per some clinical trials <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0044037#pone.0044037-Sacks1" target="_blank">[31]</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0044037#pone.0044037-MacGregor1" target="_blank">[32]</a>, in which the change in systolic pressure = −0.0598 * (mmol salt reduction)−0.0431 * (age-48)) (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0044037#pone.0044037.s017" target="_blank">Text S1</a>) <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0044037#pone.0044037-SmithSpangler1" target="_blank">[26]</a>.</p

Impact of salt reduction on cardiovascular events and deaths.

<p>Projected Reductions in Cardiovascular Events Given a Dietary Salt Reduction Target of 3 g/day over 30 years (via a linear reduction in intake of 0.1 g/year) among Urban Men, Urban Women, Rural Men, and Rural Women, According to Age Cohort. Confidence intervals reflect 2 standard deviations around the mean result from 10,000 simulations. The estimated number of averted cases per year in each cohort (incorporating the population size and rate of events in each cohort) are provided in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0044037#pone.0044037.s014" target="_blank">Table S7</a>. Panel A: Change in new and recurrent MIs. Panel B: Change in new and recurrent strokes. Panel C: Change in deaths from MIs and strokes.</p

Trends in per capita sales of unhealthy food and beverage commodities, 1997–2010 and projected to 2016.

<p>Mean growth rates 1997–2010 are labelled. Data are from the EuroMonitor 2011 dataset. LMICs defined using World Bank criteria as GDP</p

Model parameters and data sources.

<p>Model parameters and data sources.</p