Association of insulin-like growth factor-I with body composition, weight history, and past health behaviors in the very old: the Framingham Heart Study

OBJECTIVES

We examined correlates of insulin-like growth factor-I (IGF-I), an indicator of growth hormone levels, to identify factors associated with higher levels of IGF-I in old age.

DESIGN

Nested study of cross-sectional correlates and early-life predictors of IGF-I level.

SETTING

A longitudinal cohort study, the Framingham Heart Study.

PARTICIPANTS

A total of 790 men and women (mean age 78.5, range 72-94), who had weight, waist and hip circumferences measured at the time of IGF-I measurement.

MEASUREMENTS

Association of IGF-I with weight, fat distribution, functional status, nutritional indicators, and past health behaviors was assessed. We also examined IGF-I in relation to body composition derived from dual energy X-ray absorptiometry.

RESULTS

IGF-I levels declined with age in both men and women. However, low IGF-I did not show expected associations with low lean mass and increased body fat. Current functional status and grip strength were not associated with IGF-I Low IGF-I was associated with weight loss in men; the strongest associations were with indicators of poorer nutritional status in both men and women. Levels of IGF-I in old age did not vary by past health behaviors.

CONCLUSION

Although IGF-I declined with age, these data from the Framingham Heart Study did not show expected cross-sectional associations of weight, body fat, and lean mass. The strongest associations were between IGF-I and nutritional indicators. These results suggest caution may be warranted with regard to use of IGF-I as an indicator of growth hormone.

Progressive versus catastrophic disability: a longitudinal view of the disablement process

BACKGROUND

There is little epidemiologic data on the development of disability over time in older persons. This study uses prospective data from cohorts followed annually for 6 to 7 years to identify persons who developed severe disability and to characterize the time course of their disabling process and subsequent mortality.

METHODS

Incidence rates of severe disability, defined as need for help in three or more activities of daily living (ADLs), were estimated for 6,640 persons who had not reported severe disability at baseline and at the first four annual follow-up visits. Among persons developing severe disability, those who reported no need for help in ADLs in previous interviews were defined as cases of catastrophic disability, and those who had previously reported some disability in ADLs were defined as cases of progressive disability.

RESULTS

Overall, 212 subjects developed progressive and 227 developed catastrophic disability. The rates of progressive disability and catastrophic disability were 11.3 and 12.1 cases per 1,000 person-years, respectively. For both types of disability, incidence rates increased exponentially with age, but the increase was steeper for progressive disability. At ages 70-74, less than 25% of severe disability was progressive, while over age 85 progressive disability represented more than half of severe disability. Incidence rates of total and both types of severe disability were similar in men and women. Mortality after severe disability onset was extremely high. Survival was unrelated to age at disability onset and type of disability but was significantly longer in women than in men (median 3.44 vs 2.12 years; p < .0001).

CONCLUSION

Tracking the development of disability provides new and important insights into the disability experience in older men and women that are potentially relevant in planning preventive, intervention, and long-term care strategies.

Mechanism of activation of guanine nucleotide exchange factor by insulin

Insulin increases activity of the guanine nucleotide exchange factor (GEF) in Rat-1 fibroblasts transfected with human insulin receptors (HIRc cells), thereby promoting formation of the active form of p21Ras (p21Ras•GTP). In order to identify the upstream molecules mediating this aspect of insulin action, we selectively removed some of these molecules by immunoprecipitation and examined GEF activity in the post-immunoprecipitation lysated of the insulin-treated HIRc cells. The removal of Shc or Grb-2 depleted GEF activity from the cell lysates, whereas immuno-precipitation of the insulin receptors, IRS-1, PLCγ and GAP, were without effect. In summary, the current data demonstrate that a majority of cellular Ras GEF activity after insulin stimulation is associated with Shc and involves interactions among Shc, Grb-2 and Sos.

Cardiac valve replacement in relapsing polychondritis. A review

Cardiac valve replacement is a rare but not exceptional eventuality in patients with relapsing polychondritis. One case requiring aortic and mitral valve replacement and its follow up is described. From the review of the literature an additional twenty patients who required cardiac valve replacement are analyzed. The mean delay between the first onset of relapsing polychondritis and operation was 6.51 years and the mean age at operation was 38.8 years. There was a preponderance of male patients (73.7%). Aortic and mitral valves were replaced in 100% and 28.5% of patients, respectively. During the four first postoperative years 23.8% of them were reoperated for periprosthetic leak or aortic aneurysm, and during the same period 52.6% died of a cardiovascular cause. Immunosuppressive agents should be employed in patients with relapsing polychondritis and cardiovascular involvement because they seem to be more effective than steroids in severe forms of the disease. Therefore, we recommend close and prolonged follow up: firstly because there can be early paravalvular prosthetic leakage due to the friability of the tissue to which it has been anchored; secondly because aortic aneurysms occur frequently in relapsing polychondritis, may be multiple, may involve all parts of the aorta and result in fatal rupture even in asymptomatic patients; and thirdly because there can be a fatal outcome due to other organ involvement, like airway obstruction, acute glomerulonephritis, or systemic vasculitis. Prophylactic composite graft replacement of the ascending aorta associated with replacement of the aortic valve and re-implantation of the coronary arteries could avoid the need for reoperation in these high risk patients.

Thoracic aortic dissection: diagnosis with transesophageal echocardiography versus MR imaging

PURPOSE

To compare transesophageal echocardiography (TEE) and magnetic resonance (MR) imaging in the diagnosis of dissection of the thoracic aorta.

MATERIALS AND METHODS

Thirty-one consecutive patients with clinically suspected aortic dissection and 10 postoperative patients underwent transesophageal color Doppler echocardiography and MR imaging. Imaging results were compared at independent double-blind readings. Final diagnosis was obtained from consensual review of all corroborative studies.

RESULTS

MR imaging depicted the intimal flap in 95% of aortic dissections; TEE, in 86% (P < .05). In surgical patients, the sensitivity of MR in detection of residual dissection was 100% versus 86% with TEE (P < .05). The inferior extent of the dissected lumen was seen only with MR imaging. False-positive results occurred in two cases with TEE and in one with MR imaging.

CONCLUSION

MR imaging is superior to TEE in the evaluation and follow-up of dissection of the thoracic aorta. Because the availability of MR is limited, however, TEE should remain the standard modality for diagnosis.

[Thromboses of heart valve prostheses: predisposing and prognostic factors based on a study of 41 patients]

Forty one patients were admitted with a diagnosis of prosthetic valve thrombosis. One patient was thrombolyzed successfully, and 40 underwent surgical procedures. In 13 cases, prosthetic valve thrombosis occurred in the first month after valve replacement. 18 patients were in functional class IV of the NYHA classification. Among the thrombosed prostheses, 91% were mechanical, and 61% in mitral position. Adequacy of anticoagulation was the most important risk factor, as this treatment was inappropriate in 20 patients. In 10 other patients, it had been changed for medical (bleeding events, pregnancy) or surgical (non cardiac surgery) reasons. The perioperative mortality rate was high (32.4%). It was 12% in patients in functional class II and 46% in those in class IV (p < 0.05). This underlines the value of early diagnosis, in which echocardiography, especially with a transesophageal probe, takes a major place, allowing prompt surgical treatment.

Management of giant coronary artery aneurysm with fistulization into the right atrium

A giant right coronary artery aneurysm communicating with the right atrium is reported. Its diagnosis using echocardiography, computed tomography of the chest, and angiography is illustrated. The operative management of this rare cardiac pathology is described. The role of operation in such a large aneurysm is emphasized.

Effect of positioning on the breathing pattern of preterm infants

Respiration, as judged by gas exchange and pulmonary function, is improved in preterm infants kept in the prone rather than the supine position. The influence of position on the breathing pattern as documented by the pneumogram was studied in 14 stable preterm infants with recent clinical apnoea. Ten of the infants had oximetry and nasal flow studies simultaneously with the impedance pneumogram. Each infant had consecutive nocturnal pneumograms, one in the prone, one in the supine position. The infants were kept for more than six hours in the assigned position. A significant increase in apnoea density and in periodic breathing was found in the supine v the prone position (mean (SE) 4.5 (0.7)% v 2.5 (0.5)%, and 13.6 (3.2)% v 7.7 (2.2)%, respectively). There was no positional difference in the incidence of bradycardia and prolonged apnoea. The examination of obstructive apnoea, mixed apnoea, and cyanotic spells did not reveal a consistent disparity between the two positions. These findings indicate an increase in central apnoea in preterm infants kept predominantly in the supine position. Possible relations of positional changes to lung mechanics are discussed. When evaluating pneumograms, attention must be given to the position in which they were performed.

[Interrupted aortic arch. A series of 15 patients]

Between 1983 and 1989, 15 children underwent surgical repair of interrupted aortic arch at 1 to 20 days of age. The anatomical form was a Celoria and Patton type B in all patients with an associated perimembranous ventricular septal defect in all but one who had multiple ventricular septal defects, and patent ductus arteriosus. Six children had a retro-esophageal right subclavian artery, two had subaortic stenosis and two had a right-sided descending thoracic aorta. In two children with severe hypoplasia of the ascending aorta the repair was performed in one stage with two deaths due to left ventricular failure. In the other B cases, a two-stage repair was carried out. The reconstruction of the aortic arch varied according to the individual case. All children had pulmonary artery banding. Seven children survived longer than 30 days. Six of them later underwent a complete repair. The only survivors were those patients in whom the neo-aortic arch grew harmoniously. The authors conclude that: a two-stage repair gave disappointing results in this series of consecutive patients, mainly because of the poor quality of the reconstruction of the aortic arch by thoracotomy.

[Early results of coronary surgery in patients between 71 and 80 years of age]

One hundred consecutive patients aged 71 to 80 without other cardiac pathology underwent coronary bypass surgery by the same surgical team between January 1986 and May 1989. These patients were recruited from a group of 687 patients undergoing coronary bypass surgery in the same period. The indication was always based on the severity of clinical symptoms resistant to medical therapy. Recent unstable angina despite triple therapy was a particularly common indication in this group of patients (61%). Preoperative coronary angiography showed a high incidence of triple vessel (62 cases) and left main stem disease (23 cases). Double vessel (12 cases) and single vessel disease (3 cases) were less common. Preoperative myocardial infarction was observed in 35% of cases; the site was nearly always on the inferior wall. In all, 230 bypasses were performed including 23 internal mammary artery bypasses (average 2.3 bypasses per patient). Six patients developed perioperative myocardial infarction confirmed by ECG and a rise in cardiac enzymes in 4 cases and by a rise in the cardiac enzymes alone in 2 cases. The mortality was low in this group of patients (3%). This was due to strict selection of patients in this age group and also to the improvement in the techniques of myocardial protection, anaesthesia and intensive care. Our results justify the operative indications in this group of patients in whom medical therapy has failed.

[Accessory mitral tissue responsible for left ventricular outflow obstruction. Reports of 7 cases]

The authors report the medico-surgical experience of Marie Lannelongue hospital of a rare condition: accessory mitral valve tissue. Seven patients aged 2 to 28 years (average: 8.7 years) had left ventricular outflow obstruction due to accessory mitral valve tissue. The diagnostic was not obvious clinically and was based on the association of echocardiographic and angiographic data. This condition was associated with another intra-cardiac malformation in 6 of the 7 patients. Surgical treatment included resection of the accessory mitral valve tissue by an aortic or combined aorto-left atrial approach, together with correction of the associated intracardiac abnormality. The postoperative results were excellent with the regression of the ventriculo-aortic pressure gradient and the physiological integrity of the mitral valve.

Fructan and cryoprotection in ryegrass (Lolium perenne L.)

Changes in carbohydrate content and composition of ryegrass (Lolium perenne L.) cv. Reveille field-grown in Normandy were investigated from May 1987 to May 1988. During the winter period, the concentrations of high DP (degree of polymerization) fructan were the lowest whilst those of ethanol-soluble carbohydrates were the highest. Ethanol-soluble carbohydrates also accounted for most of the non-structural carbohydrates of four cultivars of Lolium perenne field-grown in central France in January 1989. The accumulation of osmotically active carbohydrates during winter leads only to a small depression of freezing point and consequently, these sugars cannot be considered as efficient cryoprotectants in ryegrass.

Beta-adrenergic receptor changes during coronary artery bypass grafting

To evaluate whether the function of beta-adrenergic receptors, essential to the biologic activity of catecholamines, is altered during coronary artery bypass grafting, we measured, in 16 patients undergoing myocardial revascularization, the density and the affinity of lymphocyte beta-adrenergic receptors before anesthesia induction (control) and at the end of cardiopulmonary bypass. Variations in the density and affinity of beta-adrenergic receptors were determined in vitro. Repeated determinations of plasma epinephrine and norepinephrine concentrations were also performed. Overall, no significant modification was observed in mean density and affinity of beta-adrenergic receptors at the end of cardiopulmonary bypass when compared with control values. However, a significant decrease (p less than 0.05) in affinity for isoproterenol was found in the six patients who had high catecholamine levels during cardiopulmonary bypass. In contrast, no significant modification of beta-adrenoreceptor affinity for isoproterenol was observed in the 10 patients who did not have this degree of adrenergic activation. In addition, beta-adrenoreceptor affinity for isoproterenol was decreased in the three patients in whom intraaortic balloon pumping was mandatory after discontinuation of cardiopulmonary bypass. We suggest that this decreased affinity of lymphocyte beta-adrenergic receptors could be related, at least in part, to a sustained adrenergic activation occurring in some patients during cardiopulmonary bypass.

The incidence of erythema multiforme, Stevens-Johnson syndrome, and toxic epidermal necrolysis. A population-based study with particular reference to reactions caused by drugs among outpatients

We carried out a study to estimate the incidence of erythema multiforme (EM), Stevens Johnson syndrome (SJS), and toxic epidermal necrolysis (TEN) requiring hospitalization and to determine which drug therapies were associated with these reactions. We reviewed the clinical records of all patients who were hospitalized with these discharge diagnoses at Group Health Cooperative (GHC) of Puget Sound, Seattle, Wash, from 1972 through 1986. During this 14-year period, an average of about 260,000 persons, with demographic characteristics similar to those of the general population, received their care from GHC, and there were about 25,000 admissions to hospitals per year at the GHC hospitals. Based on International Classification of Diseases-Adapted coding, a total of 61 suspect cases of EM, SJS, or TEN were identified from the computerized hospital discharge file. Based on record review and the application of a uniform set of diagnostic criteria, a total of 37 patients (61%) were classified as having EM, SJS, or TEN. Of these, 16 cases (43%) were attributed to drugs administered to these patients prior to hospitalization. The overall incidence of hospitalization for EM, SJS, or TEN due to all causes was 4.2 per 10(6) person-years. The incidence of TEN alone due to all causes was 0.5 per 10(6) person-years. The incidence of EM, SJS, or TEN associated with drug use were 7.0, 1.8, and 9.0 per 10(6) person-years, respectively, for persons younger than 20 years of age, 20 to 64 years of age, and 65 years of age and older. Drug therapies with reaction rates in excess of 1 per 100,000 exposed individuals include phenobarbital (20 per 100,000), nitrofurantoin (7 per 100,000), sulfamethoxazole and trimethoprim, and ampicillin (both 3 per 100,000), and amoxicillin (2 per 100,000). Overall, our data suggest that cases of EM, SJS, and TEN sufficiently severe to require hospitalization are infrequent among outpatients using well-established drug therapies. A continuing challenge is the evaluation of these severe cutaneous reactions that are associated with newly marketed or less frequently prescribed drug therapies.

[Immediate postoperative results following conservative surgery of rheumatic mitral valve insufficiency in children]

The immediate post-operative results of conservative surgery were evaluated objectively in 31 children aged under 13 years referred to us for surgical correction of severe rheumatic mitral valve regurgitation. 16 patients had pure mitral regurgitation. In the others, lesions which required additional surgery were aortic regurgitation in 7 cases, tricuspid of the mitral valve and left ventricle was studied by two-dimensional TM-mode echocardiography. This examination was combined with a pulsed doppler study in search of a possible residual mitral regurgitation signal, with special attention to the depth at which it was recorded in the left atrium -- a semi-quantitative indication of the severity of residual leakage. Two mitral valve replacements were performed, and two early reoperations were needed for residual regurgitation developed between the 5th and 8th post-operative days. Three deaths occurred due to supra-systemic pulmonary arterial hypertension. The post-operative evaluation of mitral valvuloplasty results therefore involved 25 patients. In the absence of significant residual mitral regurgitation, two-dimensional echocardiography was inconclusive since the images obtained varied considerably according to the surgical procedures performed. There was a distinct reduction of end-diastolic diameters (43.5 +/- 5.9 versus 62.1 +/- 8.7 mm pre-operatively), reflecting the disappearance or marked decrease of the pre-operative ventricular volume overload consecutive to mitral regurgitation. The reduction of end-systolic diameters was also significant (31.2 +/- 6.7 mm versus 39.2 +/- 7.1 mm pre-operatively), though less pronounced than that of end-diastolic diameters, which explains the diminution observed in the percentage of fibre shortening, although the figures remained within normal limits (28.7 +/- 9.7 p. 100 versus 37.0 +/- 6.8 p. 100).(ABSTRACT TRUNCATED AT 250 WORDS)

[Surgery for incomplete atrioventricular canal. Mid-term follow-up apropos of 128 patients]

Among 128 consecutive patients operated upon between 1972 and 1984 at the Marie-Lannelongue Surgical Centre for incomplete persistent atrioventricular canal, 102 could be followed up for periods ranging from 18 months to 11 years. Of the 23 patients lost sight of, 19 were foreigners. One patient died during the first postoperative month and two died during the following five months; there was no death thereafter. One patient developed complete atrioventricular block immediately after surgery. At the end of the follow-up period, three patients had been reoperated upon for disinsertion of the patch on the ostium primum associated in one case with massive mitral regurgitation; two complete atrioventricular blocks requiring permanent pacing had occurred some time after surgery; five patients had presented with late atrial dysrhythmia, and only six patients had signs of heart failure primarily due to residual mitral regurgitation. At radiography, the cardiothoracic ratio was reduced in 74 p. 100 of the cases from 0.60 +/- 0.08 to 0.53 +/- 0.05 (p less than 0.001), and the earlier the operation had been performed, the greater the reduction in cardiothoracic ratio (p less than 0.05). A mitral regurgitation murmur was observed in 72 p. 100 of patients immediately after surgery and in 82 p. 100 of patients at the end of the follow-up period. The murmur was usually weak (79 p. 100) with a tendency to remain stable (44 p. 100) or to increase in intensity (43 p. 100, but reoperation was necessary in only one case.(ABSTRACT TRUNCATED AT 250 WORDS)

[Surgical treatment of infectious endocarditis on a native valve. Apropos of 71 cases]

The results of surgery in a series of 71 patients operated upon for infective endocarditis on a native valve are presented. The patients' mean age was 35 years; the initial focus of infection was usually located in the mouth and the most frequent pathogens were staphylococci and streptococci. The aortic valve was most frequently involved. Only 26 patients underwent surgery after 40 days of antibiotic therapy; 34 were operated upon in a semi-emergency and 11 in an acute emergency. Pre-operative systemic embolism was common (20 cases), notably in the brain (17 cases), and 11 patients remained with sequelae. There was good correlation between the anatomical lesions found at surgery and the data obtained from pre-operative echocardiography. The operation was performed on one valve in 40 cases, on two valves in 20 cases and on three valves in 11 cases. Bioprostheses were used more often than mechanical prostheses. Hospital mortality was nil in patient who underwent elective surgery; it was 14.7 p. 100 in those operated upon in a semi-emergency and 27.3 p. 100 in those operated upon in an acute emergency. Nine patients developed late complications, mostly within 6 months of the operation; in particular, prosthesis disinsertion occurred in 4 cases, and progression of a pre-existing left cardiac failure was observed in 2 cases. In their conclusions the authors emphasize the reliability of echocardiography and the need for an early operation in cases with haemodynamic disorders in order to avoid severe myocardial failure and, if possible, systemic embolism and its fearsome sequelae.