Prediction of glycemic response to mixed meals in noninsulin-dependent diabetic subjects

Recent studies suggest the glycemic response of different mixed meals cannot be predicted from the glycemic index (GI) of individual carbohydrate foods. Postprandial glucose levels following five different mixed meals in six noninsulin-dependent diabetic volunteers were therefore assessed. Each meal comprised 50% carbohydrate, 30% fat, and 20% protein, varying only in type of carbohydrate. The carbohydrate exchanged in each meal (potato, white bread, rice, spaghetti, or lentils and barley) contributed 37% of total meal calories. The correlation between predicted glucose response and postprandial glucose area was highly significant; estimated meal GI was virtually proportional to the actual mean glycemic response. These results demonstrate that the relative glycemic effects of mixed meals can be predicted from the GI of their carbohydrate components, again stressing the importance of type of carbohydrate in regulating postprandial blood-glucose levels.     

Prevention and management of osteoporosis: consensus statements from the Scientific Advisory Board of the Osteoporosis Society of Canada. 9. Calcitonin in the treatment of osteoporosis.

OBJECTIVE: To describe potential therapeutic uses of calcitonin in the prevention and treatment of osteoporosis. OPTIONS: Parenterally and intranasally administered calcitonin (eel, salmon or human). OUTCOMES: Fracture, fracture pain and loss of bone mineral density in osteoporosis; increased bone mass, prevention of fractures, reduction of pain and improved quality of life associated with calcitonin treatment. EVIDENCE: Relevant clinical studies and reports were examined, with an emphasis on recent randomized, placebo-controlled trials. In vitro and in vivo studies of osteoclast activity were also considered. VALUES: Reducing fractures and fracture pain, increasing bone mineral density and minimizing side effects of treatment were given a high value. BENEFITS, HARMS AND COSTS: Calcitonin reduces acute pain associated with osteoporotic fractures and has been found useful in treating chronic back pain following vertebral fractures in spinal osteoporosis. It can prevent bone loss and may be effective in preventing fractures. Side effects are dose related and generally mild; they include gastrointestinal, vascular and dermatologic conditions that can be treated symptomatically or by varying the dosage. Side effects are much rarer with nasal administration than with injection. True allergic reactions are rare. RECOMMENDATIONS: Calcitonin in both intramuscular and intranasal forms can reduce the pain of acute osteoporotic vertebral fractures and may be effective in treating that associated with chronic vertebral osteoporotic fractures. Calcitonin may also prevent postmenopausal bone loss and increase bone density in those with established osteoporosis. Current evidence for long-term prevention of fractures is limited and does not support the use of calcitonin as a first-line treatment for established osteoporosis. Most side effects can be avoided with nasal administration. Further trials are needed to assess fracture prevention and effective dose ranges for treating pain and increasing bone mineral density and to determine the long-term efficacy of calcitonin in secondary osteoporosis, in premenopausal women, in men and in elderly people.     

Prevention and management of osteoporosis: consensus statements from the Scientific Advisory Board of the Osteoporosis Society of Canada. 3. Effects of ovarian hormone therapy on skeletal and extraskeletal tissues in women.

OBJECTIVE: To present recent evidence on the use of ovarian hormone therapy (OHT) for osteoporosis and outline safe and effective regimens. OPTIONS: Estrogen alone, estrogen and progestins, progestins alone; various treatment regimens. OUTCOMES: Fracture and loss of bone mineral density in osteoporosis; increased bone mass, prevention of fractures and improved quality of life associated with OHT. EVIDENCE: Relevant clinical studies and reports, including the Nurses' Health Study and the Post-menopausal Estrogen/Progestin Interventions (PEPI) Trial, were studied with emphasis on recent prospective, randomized, controlled trials. Current clinical practice was determined by survey. VALUES: Reducing fractures, increasing bone mineral density and minimizing side effects of treatment were given a high value. BENEFITS, HARMS AND COSTS: Proper management of osteoporosis minimizes injury and disability, improves quality of life and reduces the personal and social costs associated with the condition. OHT is the front-line pharmaceutical therapy for prevention and treatment of osteoporosis in post-menopausal women. In those who are able and willing to comply with therapy, OHT prevents bone loss and fractures. Hormone therapy may also decrease risk of coronary artery disease. Cyclic progestin protects against endometrial cancer in patients receiving estrogen. Potential harms include breast cancer and endometrial cancer related to dosage and duration of therapy. Mastalgia and especially resumption of menstrual bleeding affect compliance. RECOMMENDATIONS: Use of OHT should be considered as early as possible in the perimenopausal period for women at increased risk of osteoporosis. Guidelines are provided for assessment of osteoporosis risk. Physicians and their patients should take into account the absolute and relative contraindications to OHT. Women with a uterus should be given estrogen in combination with a progestin. Ideally, therapy would be continued for a minimum of 10 years beyond menopause for maximum bone protection. Women using OHT should be carefully monitored and evaluated for possible adverse events. This should include regular screening mammography, breast examination and, for some, endometrial surveillance. Specific dosages and treatment regimens are outlined.     

Measurement of the mechanical properties of the skin using the suction test

INTRODUCTION: The suction test is commonly used to study the mechanical properties of human skin in vivo. The unevenness of the stress fields complicates obtaining the intrinsic mechanical parameters of the skin in vivo because the values of the local stresses and deformations cannot be calculated directly from the displacements and forces applied by the test apparatus. In general, users only take into account the negative pressure applied and the elevation of the dome of skin drawn up in order to deduce the properties of the skin. This method has the major disadvantage of being dependent on the experimental conditions used: in particular, the size of the suction cup and the negative pressure applied. Here, we propose a full mechanical study of the test to provide rigorous results. We compare the frequently used geometric method (making the thin plate hypothesis), Timoshenko's method (which can take greater plate thicknesses into account) and finally various results obtained by the finite elements (FE) technique. METHODS: The suction test was modelled by FE with large displacements and large deformations both for orthotropic and isotropic plates. The results obtained in the elastic domain for various values of Young's modulus and of applied negative pressure were used as references and were compared with methods using analytical relationships. RESULTS: The geometric method generally used in the interpretation of suction tests gives results, which in certain configurations, are very different from those obtained by FE. The method of Timoshenko is suited to thick plates 'in contact' or embedded round the edge, the elevation of the dome and the tension and flexion stresss are analytically accessible through relationships involving four constants that are dependent on the limit conditions. Comparison with the FE results enabled the optimisation of the coefficients to adapt the relationships to the particular conditions of the suction trials. CONCLUSION: We showed the limits of the geometrical method and proposed a solution, which while remaining simple to use, gives results that are closer to reality both for the calculation of the modulus and for the determination of the state of the stresses obtained.     

Cognitive decline is associated with an accelerated rate of bone loss and increased fracture risk in women: a prospective study from the Canadian Multicentre Osteoporosis Study

Cognitive decline and osteoporosis often coexist and some evidence suggests a causal link. However, there are no data on the longitudinal relationship between cognitive decline, bone loss and fracture risk, independent of aging. This study aimed to determine the association between: (i) cognitive decline and bone loss; and (ii) clinically significant cognitive decline (≥3 points) on Mini Mental State Examination (MMSE) over the first 5 years and subsequent fracture risk over the following 10 years. A total of 1741 women and 620 men aged ≥65 years from the population-based Canadian Multicentre Osteoporosis Study were followed from 1997 to 2013. Association between cognitive decline and (i) bone loss was estimated using mixed-effects models; and (ii) fracture risk was estimated using adjusted Cox models. Over 95% of participants had normal cognition at baseline (MMSE ≥ 24). The annual % change in MMSE was similar for both genders (women −0.33, interquartile range [IQR] −0.70 to +0.00; and men −0.34, IQR: −0.99 to 0.01). After multivariable adjustment, cognitive decline was associated with bone loss in women (6.5%; 95% confidence interval [CI], 3.2% to 9.9% for each percent decline in MMSE from baseline) but not men. Approximately 13% of participants experienced significant cognitive decline by year 5. In women, fracture risk was increased significantly (multivariable hazard ratio [HR], 1.61; 95% CI, 1.11 to 2.34). There were too few men to analyze. There was a significant association between cognitive decline and both bone loss and fracture risk, independent of aging, in women. Further studies are needed to determine mechanisms that link these common conditions. © 2021 American Society for Bone and Mineral Research (ASBMR).     

Population‐Wide Impact of Non‐Hip Non‐Vertebral Fractures on Mortality

Data on long‐term consequences of non‐hip non‐vertebral (NHNV) fractures, accounting for approximately two‐thirds of all fragility fractures, are scanty. Our study aimed to quantify the population‐wide impact of NHNV fractures on mortality. The national population‐based prospective cohort study (Canadian Multicentre Osteoporosis Study) included 5526 community dwelling women and 2163 men aged 50 years or older followed from July 1995 to September 2013. Population impact number was used to quantify the average number of people for whom one death would be attributable to fracture and case impact number to quantify the number of deaths out of which one would be attributable to a fracture. There were 1370 fragility fractures followed by 296 deaths in women (mortality rate: 3.49; 95% CI, 3.11 to 3.91), and 302 fractures with 92 deaths in men (5.05; 95% CI, 4.12 to 6.20). NHNV fractures accounted for three‐quarters of fractures. In women, the population‐wide impact of NHNV fractures on mortality was greater than that of hip and vertebral fractures because of the greater number of NHNV fractures. Out of 800 women, one death was estimated to be attributable to a NHNV fracture, compared with one death in 2000 women attributable to hip or vertebral fracture. Similarly, out of 15 deaths in women, one was estimated to be attributable to a NHNV fracture, compared with one in over 40 deaths for hip or vertebral fracture. The impact of forearm fractures (ie, one death in 2400 women and one out of 42 deaths in women attributable to forearm fracture) was similar to that of hip, vertebral, or rib fractures. Similar, albeit not significant, results were noted for men. The study highlights the important contribution of NHNV fractures on mortality because many NHNV fracture types, except for the most distal fractures, have serious adverse consequences that affect a significant proportion of the population. © 2017 American Society for Bone and Mineral Research.     

Uncommon cause of mitral insufficiency: pacemaker lead malpositioning in the left ventricle. Case report]

Cardiac pacemakers' insertions may be associated with different types of complications such as lead's malposition. The authors report the observation of lead's malposition in the left ventricular chamber through the interatrial septum. This malposition is potentially dangerous because of the potent risk factor for stroke and thromboembolism that the patient might run. The diagnosis of this malposition can be done by surface electrocardiogram and thorax X-ray. However, we do insist on the importance of echocardiography and furthermore of transesophageal echocardiography which can lead to a much better choice in the treatment.     

A nonlinear elastic behavior to identify the mechanical parameters of human skin in vivo

Background/purpose: Various analyses have been performed to identify the mechanical properties of the human skin tissue in vivo . They generally use different approaches and hypotheses (behavior laws as well as mechanical tests) and the obtained results are consequently difficult to analyze and compare. In this paper, an inverse method that can be adapted to any kind of mechanical tests and behavior laws is presented.
Method: A suction deformation performed on the volar aspect of the forearm of a subject is considered. This test is modeled with the finite element method to compare the experimental and simulated curves using an inverse method that allows the skin mechanical parameters identification. This process is based on two optimization algorithms, Kalman's filter and Gauss–Newton's methods. To account for the nonlinear behavior of the skin, a specific nonlinear elastic law, which is then compared with standard linear elastic and neo-Hookean's mechanical behaviors, was developed.
Results: The obtained results first prove that neither linear elasticity nor neo-Hookean's laws can be used to model the skin. On the contrary, the nonlinear elastic model presents a relevant fit of the experimental curves. The skin thickness is also proved to be another key point to be taken into consideration.
Conclusions: The obtained results are successfully compared with literature and the reliability of the proposed method is underlined with the identification of 300 additional experimental curves. The different works we are currently focusing on are finally introduced.