INTRODUCTION Reference values for liver stiffness for healthy individuals vary worldwide. Different optimal cutoff values correspond to the stages of fibrosis in chronic liver disease.

OBJECTIVES Characterize the distribution of liver stiffness in Cuban adults without liver disease and its association with age, serum uric acid and body mass index.

METHODS A cross-sectional study was performed of 110 plasma donors recruited from the Havana Province Blood Bank January 2016 through February 2017. Measurements of liver stiffness were performed using a FibroScan elastography device on the same day of laboratory analyses and abdominal ultrasound. The Pearson coefficient was used to assess correlations, and the reference range was calculated using the mean and its 95% confidence interval.

RESULTS Liver stiffness values observed ranged from 2.2–6.3 kPa. The reference range (95% CI) for the 110 subjects without known liver disease was 4.2–4.6 kPa (mean 4.4). A positive correlation was observed between liver stiffness measurements and body mass index (r = 0.255, p <0.01) and serum uric acid (r = 0.266, p <0.01). There was no correlation between liver stiffness and age. Liver stiffness in women was similar to that of men, 4.3 (2.4–6.1) and 4.5 (2.2–6.3) kPa, respectively (p = 0.086).

CONCLUSIONS Liver stiffness in Cuban adults without liver disease ranges from 2.2–6.3 kPa. The reference range is 4.2–4.6 kPa. Body mass index and serum uric acid levels are positively associated with liver stiffness.

KEYWORDS Liver disease, liver fibrosis, hepatic cirrhosis, hepatic fibrosis, diagnostic imaging, elastography, sonoelastography, elasticity imaging techniques, tissue elasticity imaging, technology assessment, Cuba

CONTRIBUTION OF THIS RESEARCH This is the first Cuban study using FibroScan to measure liver stiffness; its results will enable better assessment of liver disease in clinical practice.

INTRODUCTION Silent myocardial ischemia is frequent in type 2 diabetics, therefore, symptoms cannot be relied upon for diagnosis and followup in these patients. Various studies relate blood lipid levels to cardiovascular diseases, and several authors describe certain lipoproteins as independent predictors of ischemia.

OBJECTIVE Identify blood lipid levels that predict silent myocardial ischemia in a type 2 diabetic population in Havana.

METHODS From May 2005 through May 2009, assessment was done of 220 asymptomatic type 2 diabetics in ten polyclinics in Havana using laboratory tests and Single-Photon Emission-Computed Tomography, synchronized with electrocardiogram, known as gated SPECT (gSPECT). Coronary angiography was used for confirmation when gSPECT detected ischemia. Patients were classified into two groups: gSPECT positive and gSPECT negative. Descriptive statistics (mean and standard deviation) were calculated for all variables and mean comparison tests were conducted. Classification trees were developed relating lipid values to gSPECT results, identifying optimal cutoff points for their use as indicators of silent myocardial ischemia in the total study population and for each sex separately.

RESULTS GSPECT found silent myocardial ischemia in 29.1% of those examined, and 68.4% of angiograms found multivessel disease. gSPECT-positive diabetics had higher levels of total cholesterol, LDL, and triglycerides (p < 0.05). HDL levels were lower in this group (p < 0.05). Classification trees showed optimal cutoff points, indicators for silent ischemia, for: HDL ≤44 mg/dL, LDL >119.9 mg/dL, and triglycerides >107.2 mg/d; 80.4% of diabetics with these HDL and triglyceride values had ischemia. HDL was the most important normalized variable when the entire population was analyzed. Analysis by sex showed a greater percentage of silent ischemia in men (33.3%) than in women (24.8%). The most important normalized variables were LDL of >100.8 mg/dL for men and HDL of ≤44 mg/dL for women.

CONCLUSIONS A considerable percentage of the study population had silent myocardial ischemia. Type 2 diabetics with ischemia had higher levels of total cholesterol, LDL and triglycerides. HDL levels were significantly lower in these patients. The association of low HDL with high triglycerides was a strong indicator of myocardial ischemia in type 2 diabetics without clinical cardiovascular signs.

KEYWORDS Lipids, type 2 diabetes, silent myocardial ischemia, decision trees, diagnostic imaging, Single-Photon Emission-Computed Tomography, cardiac-gated SPECT, early detection, Cuba

Introduction Diagnostic evaluation of the musculoskeletal system has traditionally been based on medical history, physical examination, and x-rays (techniques that provide limited information), and more recently on computerized axial tomography and magnetic resonance imaging (both very expensive). Ultrasound, a non-invasive and less expensive method, has become an indispensable tool for diagnosing overuse sports injuries. The Imaging Department at the Cuban Sports Medicine Institute (abbreviated in Spanish as IMD) developed a preventive ultrasound diagnostic imaging method and has applied it for the last 15 years as part of the IMD’s medical management of high-performance athletes.

Objectives Identify normal ultrasound patterns for knee structures and extensor mechanism alignment, and perform ultrasound imaging of the knee on asymptomatic, high-performance athletes to detect alterations and endogenous predisposing factors to overuse sports injuries as a basis for adopting preventive action.

Methods A descriptive cross-sectional study was conducted of 300 non-athletes (control) and 100 Cuban Olympic athletes (preselected for the 2000 Olympic Games in Sydney, Australia). The IMD’s Preventive Ultrasound Diagnostic Imaging Method was used to perform static and dynamic ultrasound examinations of both knees of all subjects (800 knees total) to determine normal patterns, detect structural alterations in the knee, and determine extensor mechanism malalignment. For the latter, Anillo’s Patellofemoral Congruence Ultrasound Method was applied to determine the degree of patellar lateralization (RAB angle). Data was processed using descriptive statistics. To compare the ratio of ultrasound knee alterations detected, the Chi-square test was used. Percentiles were calculated based on data from the 600 non-athlete knees and were processed using the SPSS statistics application.

Results Of the 100 athletes studied, 57 were found to have subclinical alterations in one or both knees, distributed as follows: synovitis (30), extensor mechanism malalignment (26), infrapatellar fat pad distortion (15), meniscal echostructure modification (14), ligament echostructure alteration (11), and articular cartilage alteration (7). Analysis of the control group findings established that RAB angle values greater than 13° for both sexes suggest excessive patellar lateralization with respect to the axial axis of the femur, potentially an endogenous risk factor favoring injury.

Conclusions Preventive ultrasound diagnostic imaging of the knee, performed using IMD’s ultrasound scanning methodology and incorporating the normal ultrasound patterns described in this study, enables diagnosis of distortions in the articular and periarticular echostructure prior to the onset of clinical symptoms, as well as observation of endogenous predisposing factors linked to overuse sports injuries. As a result, appropriate measures can be adopted to prevent such injuries and to tailor medical management of high-performance athletes.

Keywords Diagnostic imaging, ultrasound diagnosis, knee, knee injuries, sports medicine, athletic injuries, sports injuries