Newly discovered cichlid fish biodiversity threatened by hybridization with non-native species

Invasive freshwater fishes are known to readily hybridize with indigenous congeneric species, driving loss of unique and irreplaceable genetic resources. Here we reveal that newly discovered (2013-2016) evolutionarily significant populations of Korogwe tilapia (Oreochromis korogwe) from southern Tanzania are threatened by hybridization with the larger invasive Nile tilapia (Oreochromis niloticus). We use a combination of morphology, microsatellite allele frequencies and whole genome sequences to show that O. korogwe from southern lakes (Nambawala, Rutamba and Mitupa) are distinct from geographically disjunct populations in northern Tanzania (Zigi River and Mlingano Dam). We also provide genetic evidence of O. korogwe × niloticus hybrids in three southern lakes and demonstrate heterogeneity in the extent of admixture across the genome. Finally, using the least admixed genomic regions we estimate that the northern and southern O. korogwe populations most plausibly diverged ~140,000 years ago, suggesting that the geographical separation of the northern and southern groups is not a result of a recent translocation, and instead these populations represent independent evolutionarily significant units. We conclude that these newly discovered and phenotypically unique cichlid populations are already threatened by hybridization with an invasive species, and propose that these irreplaceable genetic resources would benefit from conservation interventions.

1145 Longitudinal Association Between Circadian Activity Rhythms And Risk Of Incident Parkinson’s Disease In Older Men

Introduction

Disruption in circadian activity rhythms are very common in older adults, particularly among those with neurodegenerative diseases. However, the longitudinal association between circadian disruption and subsequent risk of developing neurodegenerative diseases, including Parkinson’s disease (PD), is unclear.

Methods

We examined rest-activity rhythms in 2930 community-dwelling older men (mean age 76.3 ± 5.5 years) without PD and followed them for incident PD over the next 11 years. 24-h rest-activity rhythm parameters (amplitude, mesor, robustness, acrophase) were generated by wrist actigraphy-extended cosinor analysis. Incident PD cases were identified based on physician-diagnosed PD between 2005 and 2016. Logistic regression was used to determine the association between quartiles of rest-activity parameters and risk of incident PD.

Results

78 (2.7%) men developed PD during 11 years of follow-up. The risk of PD increased with decreasing circadian amplitude (strength of the rhythm), mesor (mean level of activity) or robustness (how closely activity follows a cosine 24h pattern); p for trend across quartiles <0.05. After accounting for demographics, clinic site, education, depressive symptoms, body mass index, physical activity, benzodiazepine use, alcohol, caffeine, smoking, comorbidities and baseline cognition, those in the lowest quartile of amplitude, mesor or robustness had approximately three times the risk of developing PD compared to those in the highest quartile of amplitude [ORs (95% CI)= 3.11 (1.54-6.29)], mesor [3.04 (1.54-6.01)] and robustness [2.65 (1.24-5.66)]. The association remained after further adjustment for nighttime sleep disturbances and sleep duration. These associations were somewhat attenuated, but the pattern remained similar after excluding PD cases developed within 2 years after baseline. Acrophase was not significantly associated with risk of PD.

Conclusion

Older men with reduced circadian rhythmicity had an increased risk of incident PD over 11 years. Circadian disruption in the elderly may represent an important prodrome or risk factor for PD. Randomized trials should evaluate whether strategies to improve circadian function impact risk of PD.

Support

This work was supported by the NIA, NIAMS, NCATS, NIH Roadmap for Medical Research and the NHLBI under the grant numbers: U01AG027810, U01AG042124, U01AG042139, U01AG042140, U01AG042143, U01AG042145, U01AG042168, U01AR066160, UL1TR000128, R01HL071194, R01HL070848, R01HL070847, R01HL070842, R01HL070841, R01HL070837, R01HL070838, and R01HL070839.

0388 Predictors of Incident Reduced Sleep Efficiency in Community-Dwelling Older Women

Introduction

There is a paucity of longitudinal studies with sleep efficiency (SE) as an outcome measure. Our objective was to examine potential risk factors for incident reduced SE among community-dwelling women in late life.

Methods

We studied 700 women (mean age 82.5 [SD=3.0] years) with a SE ≥70% at the Year 16 (2002-04) visit of the Study of Osteoporotic Fractures with a follow-up measure of SE at the Year 20 (2006-08) visit. SE (percentage of time sleeping while in bed) at both visits was measured using a wrist actigraph with data collected for an average of four 24-hour periods. Women were classified as having incident reduced SE if they had SE <70% at Year 20. Logistic regression was used to estimate the associations between potential risk factors (demographics, lifestyle, use of medications, self-reported medical conditions, functional impairment, frailty, mental and physical health) at Year 16 and reduced SE at Year 20. The association of each candidate risk factor with reduced SE at Year 20 was examined in models adjusted for age, clinical site and continuous SE at Year 16. Candidate risk factors with Benjamin Hochberg false-discovery rate q-values <0.10 were included in a final multivariate model.

Results

Among the 700 eligible women, 62 (8.9%) developed incident reduced SE between the Year 16 and Year 20 visits. After adjusting for age, site and baseline SE, antidepressant use [OR=3.06; 95% CI: 1.50-6.25], benzodiazepine use [OR=2.97; 95% CI: 1.30-6.80] and the presence of hypertension [OR=2.83; 95% CI: 1.47-5.45] at Year 16 were independently associated with a higher odds of having reduced SE at follow-up.

Conclusion

These findings suggest that antidepressant use, benzodiazepine use and hypertension are risk factors or markers for the development of reduced sleep efficiency in older women. Future studies are warranted to examine the underlying mechanisms for these associations.

Support

The Study of Osteoporotic Fractures (SOF) is supported by National Institutes of Health funding. The National Institute on Aging (NIA) provides support under the following grant numbers: R01 AG005407, R01 AR35582, R01 AR35583, R01 AR35584, R01 AG005394, R01 AG027574, and R01 AG027576.

Performance of FRAX in a cohort of community-dwelling, ambulatory older men: the Osteoporotic Fractures in Men (MrOS) study

We evaluated performance of FRAX in older men who participated in the Osteoporotic Fractures in Men (MrOS) study.

INTRODUCTION

FRAX has been extensively studied in women, but there are few studies of its performance in men.

METHODS

FRAX estimates for 10-year hip fracture and major osteoporotic fracture (MOF; either hip, clinical spine, forearm, or shoulder) were calculated from data obtained from MrOS participants and compared to observed 10-year fracture cumulative incidence calculated using product limit estimate methods, accounting for competing mortality risk.

RESULTS

Five thousand eight hundred ninety-one men were followed for an average of 8.4 years. Without bone mineral density (BMD) in the FRAX model, the mean 10-year predicted fracture probabilities for hip and MOF were 3.5% and 8.9%, respectively; addition of BMD to the calculations reduced these estimates to 2.3% and 7.6%. Using FRAX without BMD, predicted quintile probabilities closely estimated cumulative incidence of hip fracture (range of observed to predicted ratios 0.9-1.1). However, with BMD in the FRAX calculation, observed to predicted hip fracture probabilities were not close to unity and varied markedly across quintiles of predicted probability. For MOF, FRAX without BMD overestimated observed cumulative incidence (range of observed to predicted ratios 0.7-0.9) and addition of BMD did not improve this discrepancy (range of observed to predicted ratios 0.7-1.1). Addition of BMD to the calculation had mixed effects on the discriminatory performance of FRAX, depending on the analysis tool applied.

CONCLUSION

Among this cohort of community-dwelling older men, the FRAX risk calculator without BMD was well calibrated to hip fracture but less well to MOF.

Outcomes and predicting response in anaemic chemotherapy patients treated with epoetin alfa. A multicentre, 4-month, open-label study in Australia and New Zealand

BACKGROUND

The aim of the study was to evaluate the effectiveness, safety, and clinical outcomes of erythropoietin therapy in the treatment of anaemic cancer subjects receiving chemotherapy and to examine hypochromic red blood cell measurement as an indicator of functional iron sufficiency and as a predictor of responsiveness or non-responsiveness to erythropoietin therapy.

METHODS

Patients who had a non-myeloid malignancy, had Hb < or = 11.0 g/dL, had a life expectancy of more than 6 months, were 18 years or older, were receiving chemotherapy and would continue to be treated for at least 2 months were given s.c. epoetin alfa three times a week.

RESULTS

Haemoglobin levels increased significantly at all time periods compared with baseline and the number of transfusions received decreased significantly at all time periods compared with baseline. Quality of life as measured by Functional Assessment of Cancer Therapy-Anaemia showed significant increases at months 2 and 4 and there were significant improvements in the fatigue subscale at both time points (P < 0.05). Significant improvements at end-point were observed for the physical, emotional and functional well-being, and additional concern subscales (all P < 0.05). Haematocrit and reticulocytes increased significantly at end-point compared with at baseline (haematocrit 33.4 vs 28.3%, P < 0.001; reticulocytes 105.8 vs 78.6 x 10(9)/dL, P = 0.005). The percentage of hypochromic red blood cells did not show predictive value for response to treatment status.

CONCLUSION

Epoetin alfa improved haemoglobin levels and quality of life in anaemic cancer patients receiving chemotherapy.

Preclinical cognitive decline and subsequent sleep disturbance in older women

OBJECTIVE

To determine whether longitudinal cognitive decline is associated with increased risk of sleep disturbance in older, nondemented, community-dwelling women.

METHODS

We studied 2,474 women (mean age 68.9 years) who were part of a prospective study started in 1986; women with baseline or follow-up evidence of possible dementia were excluded. Cognitive data were gathered over 15 years for modified Mini-Mental State Examination (mMMSE) and 13 years for Trails B; cognitive decline was defined as declining >1.5 SDs on the mMMSE (> or =3 points) or Trails B (>92 seconds). Sleep disturbance was measured objectively using actigraphy (Sleepwatch-O, Ambulatory Monitoring) at the 15-year follow-up visit; measures included total sleep hours, sleep efficiency, sleep latency, napping, and time awake after sleep onset (WASO).

RESULTS

During follow-up, 11% of women declined on mMMSE and 15% on Trails B. Cognitive decliners were more likely than non-decliners to experience sleep disturbance at follow-up on most measures. For women who declined on mMMSE, adjusted ORs (aOR) (95% CI) were 1.71 (1.24, 2.37) for sleep efficiency <70%, 1.57 (1.12, 2.21) for sleep latency > or =1 hour, and 1.43 (1.07, 1.92) for WASO > or =90 minutes. Results were similar for women who declined on Trails B; in addition, these women were more likely to nap >2 hours per day (aOR: 1.73; 95% CI: 1.28, 2.33). Cognitive decline on either test was not associated with total sleep time.

CONCLUSIONS

Cognitive decline is associated with sleep disturbance in nondemented community-dwelling elderly women.

Glycosylated hemoglobin level and development of mild cognitive impairment or dementia in older women

BACKGROUND

Biological mechanisms linking diabetes and cognition continue to grow, yet the association remains controversial in elders. Whether glycosylated hemoglobin (HbA1C) level, a marker of glucose control, is predictive of the development of cognitive impairment or dementia is unknown. We determined the association between HbA1C level and risk of developing cognitive impairment in older women, mostly without diabetes.

METHODS

We studied 1983 postmenopausal women (mean age, 67.2 years) with osteoporosis who had HbA1C level measured at baseline. Development of mild cognitive impairment (MCI) or dementia over 4 years was determined as part of a dementia ancillary study. We analyzed risk of MCI or dementia for every 1% of HbA1C as well as risk associated with HbA1C >or= 7%.

RESULTS

The mean level of HbA1C was 5.8% (range 3.0% to 12.1%) and 86 (4.3%) women developed MCI or dementia. For every 1% increase in HbA1C, women had a greater age-adjusted likelihood of developing MCI (OR= 1.50; 95% CI 1.14-1.97) and of developing MCI or dementia (OR=1.40; 95% CI 1.08 - 1.83). For those with HbA1C level >or= 7% (n=49), the age-adjusted risk for developing MCI was increased nearly 4-fold (OR= 3.70; 95% CI 1.51-9.09) and was increased nearly 3-fold for developing MCI or dementia (OR=2.86; 95% CI 1.17-6.98). When we excluded women with diagnosed diabetes (n=53), the association between HbA1C and MCI lessened somewhat but remained elevated (unadjusted OR=1.59; 95% CI 1.01-2.50; age-adjusted OR=1.42; 95% CI 0.89-2.28). Multivariate analyses adjusted for age, education, race, depression, alcohol use and treatment with raloxifene yielded similar results.

INTERPRETATION

We found an association between HbA1C level and risk of developing MCI or dementia in postmenopausal osteoporotic women primarily without diabetes. Our findings support the hypothesis that glucose dysregulation is a predictor for cognitive impairment.

Diabetes, impaired fasting glucose, and development of cognitive impairment in older women

OBJECTIVE

To investigate the association between diabetes and impaired fasting glucose (IFG) and cognition and risk of developing both dementia and mild cognitive impairment (MCI) in older women.

METHODS

The authors analyzed data from a 4-year randomized trial of raloxifene among 7,027 osteoporotic postmenopausal women (mean age, 66.3 years) at 178 sites. Diabetes was defined by history, fasting blood glucose > or =7.0 mmol/L (> or =126 mg/dL), or use of hypoglycemic agents; IFG was defined as fasting glucose <7.0 mmol/L but >6.11 mmol/L (110 mg/dL); all others were considered to have normal glucose (NG). The main outcome was baseline and 4-year change on five standardized cognitive tests (z scores with lower scores indicating worse performance) and risk of developing clinically significant impairment (dementia, mild cognitive impairment, or very low cognitive score).

RESULTS

A total of 267 (3.8%) women had diabetes and 297 (4.2%) had IFG. Women with IFG had worse baseline cognitive scores compared to women with NG but better scores than diabetics (age-adjusted composite z score based on five tests: NG 0.40, 95% CI 0.30 to 0.49; IFG 0.14, 95% CI -0.36 to 0.64; diabetics -0.78, 95% CI -1.23 to -0.33; p < 0.001). There was greater 4-year decline among diabetics (age and treatment-adjusted composite z score: NG -0.05, 95% CI -0.16 to 0.05; IFG 0.11, 95% CI -0.53 to 0.75; diabetics -1.00, 95% CI -1.50 to -0.50; p = 0.001). Further adjustment for education, race, and depression led to similar results. Risk of developing cognitive impairment among women with IFG or diabetes was increased by almost twofold (age and treatment-adjusted OR = 1.64; 95% CI 1.03 to 2.61 for IFG; OR = 1.79; 95% CI 1.14 to 2.81 for diabetics).

CONCLUSIONS

Diabetic as well as pre-diabetic women have impaired cognitive performance and greater risk of developing cognitive impairment.

Antiepileptic drug use increases rates of bone loss in older women: A prospective study

OBJECTIVE

To test the hypothesis that older women with antiepileptic drug (AED) use have increased rates of bone loss.

METHODS

AED use was ascertained and calcaneal and hip bone mineral density (BMD) measured in a cohort of 9,704 elderly community-dwelling women enrolled in the Study of Osteoporotic Fractures, and they were followed prospectively for changes in BMD. Current use of AED was assessed by interview, with verification of use from medication containers at baseline and follow-up examinations. Women were classified as continuous users, partial (intermittent) users, or nonusers. Rates of change in BMD were measured at the total hip and two subregions (average 4.4 years between examinations) and at the calcaneus (average 5.7 years between examinations).

RESULTS

After adjustment for confounders, the average rate of decline in total hip BMD steadily increased from -0.70%/year in nonusers to -0.87%/year in partial AED users to -1.16%/year in continuous AED users (p value for trend = 0.015). Higher rates of bone loss were also observed among continuous AED users at subregions of the hip and at the calcaneus. In particular, continuous phenytoin users had an adjusted 1.8-fold greater mean rate of loss at the calcaneus compared with nonusers of AED (-2.68 vs -1.46%/year; p < 0.001) and an adjusted 1.7-fold greater mean rate of loss at the total hip compared with nonusers of AED (-1.16 vs -0.70%/year; p = 0.069).

CONCLUSIONS

Continuous AED use in elderly women is associated with increased rates of bone loss at the calcaneus and hip. If unabated, the rate of hip bone loss among continuous AED users is sufficient to increase the risk of hip fracture by 29% over 5 years among women age 65 years and older.

Changes in biochemical markers of bone turnover in women treated with raloxifene: influence of regression to the mean

Measures with extreme magnitude are most likely to be the result of measurement variability. Repeated measurements genuinely lessen such variability, leading to a phenomenon known as regression to the mean (RTM), which may affect biochemical markers of bone turnover. We therefore studied four markers of bone turnover in the Multiple Outcomes of Raloxifene Evaluation (MORE) trial--serum procollagen type I C-propeptide (PICP), osteocalcin (OC), bone-specific alkaline phosphatase (BAP) and urinary type I collagen breakdown product (CTX)--among the 1704 women treated with raloxifene who had marker measurements and were at least 70% adherent, and among 915 control group patients. We examined the existence of RTM, and applied a method of adjustment for RTM of both baseline and follow-up results. We found that women who had the most extreme values tended to go in the opposite direction with the subsequent measurement, i.e., exhibited a pattern of RTM. For example, among women whose urinary CTX decreased at least 60% in the first 6 months, 61% had an increase in the next 6 months; and among those who had an increase in the first 6 months, 81% had a decrease in the next 6 months. We found a similar pattern for each of the four markers. When adjusting for RTM we obtained estimated true values of both baseline values and change in markers. These estimated true values were substantially different from the observed value when the latter was further from the mean. For example, for a 10% increase in urinary CTX in the first 6 months, after accounting for RTM we estimate that there was in fact a 3% decrease (80% confidence interval: -38% to 53%). We conclude that the few initial extreme marker responses observed in women treated with raloxifene represent RTM, and that one practical consequence is that patients with an increase in markers during the first 6 months should be continued on raloxifene therapy, because the values usually decrease later on.

Resuscitation in the out-of-hospital setting: medical futility criteria for on-scene pronouncement of death

The complete and irreversible cessation of life is often difficult to determine with complete confidence in the dynamic environment of out-of-hospital emergency care. As a result, resuscitation efforts often are initiated and maintained by emergency medical services (EMS) providers in many hopeless situations. Medical guidelines are reviewed here to aid EMS organizations with respect to decisions about: 1) initiating or waiving resuscitation efforts; 2) the appropriate duration of resuscitation efforts; and 3) recommended procedures for on-scene or prehospital pronouncement of death (termination of resuscitation). In cases of nontraumatic cardiac arrest, few unassailable criteria, other than certain physical signs of irreversible tissue deterioration, exist for determining medical futility at the initial encounter with the patient. Thus, the general medical recommendation is to attempt to resuscitate all patients, adult or child, in the absence of rigor mortis or dependent lividity. Conversely, wellfounded guidelines now are available for decisions regarding termination of resuscitation in such patients once they have received a trial of advanced cardiac life support. In practice, however, the final decision to proceed with on-scene pronouncement of death for these patients may be determined more by family and provider comfort levels and the specific on-scene environment. For patients with posttraumatic circulatory arrest, the type of injury (blunt or penetrating), the presence of vital signs, and the electrocardiographic findings are used to determine the futility of initiating or continuing resuscitation efforts. In general, patients who are asystolic on-scene are candidates for on-scene pronouncement, regardless of mechanism. With a few exceptions, blunt trauma patients with a clearly associated mechanism of lethal injury are generally candidates for immediate cessation of efforts once they lose their pulses and respirations. Regardless of the medical futility criteria, specialized training of EMS providers and targeted related testing of operational issues need to precede field implementation of on-scene pronouncement policies. Such policies also must be modified and adapted for local issues and resources. In addition, although the current determinations of medical futility, as delineated here, are important to establish for societal needs, the individual patient's right to live must be kept in mind always as new medical advances are developed.

Spinal immobilization in the field: clinical clearance criteria and implementation

Awareness of the health and financial repercussions of unnecessary immobilization has made cervical spinal immobilization controversial in out-of-hospital care. Clinical criteria for clearance of the cervical spine in the hospital based on mechanism of injury have been supported by many trauma centers. However, implementation of clinical criteria for cervical spinal clearance in out-of-hospital settings is not as well validated by multicenter studies or accepted by many emergency departments. This consensus group recommends that clinical criteria to determine "low-risk" patients be available for use by emergency medical services providers in out-of-hospital settings; however, training, audits, quality management, integration into the medical community, and extent of program implementation should be decided based on individual emergency medical services systems.

Concepts and application of prehospital ventilation

Airway management and optimal ventilation are crucial aspects of managing out-of-hospital medical emergencies. The goals in these situations are controlled ventilation and optimized inspiratory time, expiratory time, and airflow. Numerous techniques and devices are available to deliver oxygen-enriched air to patients during resuscitation. The bag-valve-mask (BVM) is one of the most common devices used to provide ventilation, although the American Heart Association ranks BVM devices lower in preference than other ventilation adjuncts, such as emergency and transport ventilators (ETVs) and pocket masks. The clearly documented limitations of BVM ventilation and its widespread use in the United States underscore the need to improve ventilation practices during care provided by emergency medical services (EMS) personnel. As part of that improvement, ETVs clearly have a role in the prehospital setting. These devices should be available on every ambulance, and the ability to use ETVs should be part of each EMS provider's skill set. Furthermore, all patients requiring emergency ventilation must be adequately monitored, including continuous monitoring of end-tidal carbon dioxide concentrations. As with any other skill, ventilation requires attention during initial training, continuing education and skill reinforcement, and quality review.

Dehydration activates an NF-kappaB-driven, COX2-dependent survival mechanism in renal medullary interstitial cells

Renal prostaglandin (PG) synthesis is mediated by cyclooxygenase-1 and -2 (COX1 and COX2). After dehydration, the maintenance of normal renal function becomes particularly dependent upon PG synthesis. The present studies were designed to examine the potential link between medullary COX1 and COX2 expression in hypertonic stress. In response to water deprivation, COX2, but not COX1, mRNA levels increase significantly in the renal medulla, specifically in renal medullary interstitial cells (RMICs). Water deprivation also increases renal NF-kappaB-driven reporter expression in transgenic mice. NF-kappaB activity and COX2 expression could be induced in cultured RMICs with hypertonic sodium chloride and mannitol, but not urea. RMIC COX2 expression was also induced by driving NF-kappaB activation with a constitutively active IkappaB kinase alpha (IKKalpha). Conversely, introduction of a dominant-negative IkappaB mutant reduced COX2 expression after hypertonicity or IKKalpha induction. RMICs failed to survive hypertonicity when COX2 was downregulated using a COX2-selective antisense or blocked with the selective nonsteroidal anti-inflammatory drug (NSAID) SC58236, reagents that did not affect cell survival in isotonic media. In rabbits treated with SC58236, water deprivation induced apoptosis of medullary interstitial cells in the renal papilla. These results demonstrate that water deprivation and hypertonicity activate NF-kappaB. The consequent increase in COX2 expression favors RMIC survival in hypertonic conditions. Inhibition of RMIC COX2 could contribute to NSAID-induced papillary injury.

Rate of bone loss is associated with mortality in older women: a prospective study

Older women with low bone density have an increased risk of fracture, cardiovascular disease, and mortality. However, it is not known whether this association is caused by ongoing bone loss or by lower bone mass earlier in life. To determine whether rate of bone loss is associated with total and cause-specific mortality, we prospectively studied 6046 women aged 65 years or older who had serial bone mineral density (BMD) measurements as a part of the Study of Osteoporotic Fractures. Rates (mean +/- SD) of loss of BMD at the heel (for a mean of 5.7 years) and hip (for a mean of 3.5 years) were estimated. Cause-specific mortality was ascertained from death certificates and hospital records. BMD loss at the heel was 5.9 +/- 6.0 mg/cm2 per year (1.5 +/- 1.5%) and BMD loss at the hip was 4.1 +/- 10.2 mg/cm2 per year (0.6 +/- 1.4%). During an average follow-up of 3.2 years after the second measurement of BMD, 371 deaths occurred. Each SD increase in BMD loss at the hip was associated with a 1.3-fold (95% CI, 1.1-1.4) increase in total mortality, adjusted for age, baseline BMD, diabetes, hypertension, incident fractures, smoking, physical activity, health status, weight loss, and calcium use. In particular, hip BMD loss was associated with increased mortality from coronary heart disease (relative hazard [RH] = 1.3 per SD; 95% CI, 1.0-1.8) and pulmonary diseases (RH = 1.6 per SD; 95% CI, 1.1-2.5). The findings were similar for bone loss at the heel, except there was no significant association with pulmonary mortality. These results raise the possibility that bone loss may share common etiologies with coronary and pulmonary diseases.

Monitoring osteoporosis therapy with bone densitometry: misleading changes and regression to the mean. Fracture Intervention Trial Research Group

CONTEXT

The principle of "regression to the mean" predicts that patients with unusual responses to treatment might represent outliers who are likely to have more typical responses if treatment is continued without change.

OBJECTIVE

To test whether women who lose bone mineral density (BMD) during the first year of treatment for osteoporosis continue to lose BMD if the same treatment is continued beyond 1 year.

DESIGN AND SETTING

Two randomized, double-blind, placebo-controlled trials in 11 US clinical research centers for the Fracture Intervention Trial and 180 centers in the United States and other countries for the Multiple Outcomes of Raloxifene Evaluation Trial.

PARTICIPANTS AND INTERVENTIONS

Postmenopausal women with low BMD assigned to treatment with 5 mg/d of alendronate sodium in the Fracture intervention Trial who completed 2 years of BMD monitoring and adhered to study medication (n = 2634), and postmenopausal women with osteoporosis assigned to treatment with 60 or 120 mg/d of raloxifene hydrochloride in the Multiple Outcomes of Raloxifene Evaluation trial who similarly completed 2 years of monitoring while adhering to study medication (n = 3954).

MAIN OUTCOME MEASURES

Baseline, 12-, and 24-month hip and spine BMD.

RESULTS

Women with the greatest loss of BMD during the first year of treatment were the most likely to gain BMD during continued treatment. Specifically, among women taking alendronate whose hip BMD decreased by more than 4% during the first year, 83% (95% confidence interval [CI], 82%-84%)had increases in hip BMD during the second year, with an overall mean increase of 4.7%. In contrast, those who seemed to gain at least 8% during the first year lost an average of 1% (95% CI, 0.1%-1.9%) during the next year. Similar results were observed among women taking raloxifene for 2 years.

CONCLUSIONS

Our data suggest that most women who lose BMD during the first year of treatment with alendronate or raloxifene will gain BMD if the same treatment is continued for a second year. These results illustrate the principle of regression to the mean and suggest that effective treatments for osteoporosis should not be changed because of loss of BMD during the first year of use.

Depressive symptoms and cognitive decline in nondemented elderly women: a prospective study

BACKGROUND

The association between depressive disorders and subsequent cognitive decline is controversial. We tested the hypothesis that elderly women (aged 65 years and older) without dementia but with depressive symptoms have worse cognitive function and greater cognitive decline than women with few or no symptoms.

METHODS

As part of an ongoing prospective study, we evaluated 5781 elderly, mostly white, community-dwelling women. Women completed the Geriatric Depression Scale short form. Three cognitive tests--Trails B, Digit Symbol, and a modified Mini-Mental State Examination--were administered at baseline and approximately 4 years later. Baseline, follow-up, and change scores for the cognitive tests were analyzed by analysis of covariance and Kruskal-Wallis analysis; the odds of cognitive deterioration (> or =3-point decline on the modified Mini-Mental State Examination) were determined by logistic regression.

RESULTS

At baseline, 211 (3.6%) of the women had 6 or more depressive symptoms. Only 16 (7.6%) of these women were receiving antidepressant medication. Increasing symptoms of depression were associated with worse performance at baseline and follow-up on all 3 tests of cognitive function (P<.001 for all comparisons). For example, the baseline Digit Symbol score (mean +/- SD) was 45.5 +/- 10.7 among women with 0 to 2 symptoms of depression, 40.3 +/- 10.7 for women with 3 to 5 symptoms, and 39.0 +/- 11.3 for women with 6 or more symptoms. After adjusting for the baseline score, cognitive change scores were also inversely associated with the number of depressive symptoms (P<.001 for all comparisons). Odds ratios for cognitive deterioration using 0 to 2 symptoms as the reference were 1.6 (95% confidence interval, 1.3-2.1) for 3 to 5 symptoms and 2.3 (95% confidence interval, 1.6-3.3) for 6 or more symptoms. Results were similar after being adjusted for education, age, health status, exercise, alcohol use, functional status, and clinic site.

CONCLUSIONS

Depressive symptoms in older women are associated with both poor cognitive function and subsequent cognitive decline. Mechanisms underlying the association between these 2 common conditions need further exploration.

Utility of percentage of births to teenagers as a surrogate for the teen birth rate

OBJECTIVES

The teen birth rate is commonly used in comparing regional variation in teen pregnancies, but local teen birth rates are not always available. In this study the percentage of all births that are to teens was evaluated for its utility as a surrogate for the teen birth rate.

METHODS

Rank correlation and sensitivity and specificity analyses were used.

RESULTS

The Spearman rank correlations between percentage of teen births (PTB) and teen birth rate (TBR) were .995, .906, and .841 for the 3 age groups suggesting that it may be reasonable to employ PTB to prioritize zip codes. Zip codes with upper quartile levels of percentages of teen births identified zip codes with upper quartile levels of TBR with a sensitivity of 83.8%, 68.8%, and 65%; a false-positive rate of 2.1%, 8.6%, and 10%; and a positive predictive value of 89.3%, 67.6%, and 67.5% for the age groups 10 through 14, 15 through 17, and 18 through 19 years.

CONCLUSIONS

The percentage of births to teens is a useful surrogate for teen birth rate in California, especially among younger teenagers.

Physical examination during space flight

OBJECTIVE

To develop techniques for conducting a physical examination in microgravity and to describe and document the physiologic changes noted with use of a modified basic physical examination.

DESIGN

On the basis of data gathered from physical examinations on KC-135 flights, three physical variables were assessed serially in astronauts during two shuttle missions (of 8- and 10-day duration, respectively). Preflight, in-flight, and postflight examinations were conducted by trained physician-astronauts or flight surgeons, who used this modified examination.

MATERIAL AND METHODS

Five male and two female crewmembers participated in the "hands-on" physical examination of all physiologic systems except the genitourinary system. Level of edema, intensity of bowel sounds, and peripheral reflexes were assessed and graded.

RESULTS

This investigation identified unique elements of a physical examination performed during space flight that will assist in the development of standard methods for conducting examinations of astronauts in weightlessness. In addition, demonstrable changes induced by microgravity were noted in most physiologic systems examined.

CONCLUSION

The data support the hypothesis that the microgravity examination differs from that conducted on earth or in a 1g environment. In addition, alterations in the physiologic response can be detected with use of hands-on technique. These data are invaluable in the development of optimal medical care for humans in space.

Bungee jumper's foot drop peroneal nerve palsy caused by bungee cord jumping

Peroneal nerve injury is a common peripheral neuropathy from a variety of conditions and injuries. We encountered a case of peroneal nerve palsy in a professional bungee cord jumper. Review of the literature showed no previous report of this particular injury in bungee cord jumping.

Sexual differences in lipoprotein composition in a family with dyslipidemic hypertension with premature atheroschlerosis: deficiency of high-density lipoprotein-L and high-density lipoprotein-M "apolipoprotein-I alone" particle

This article describes a family with a high incidence of premature atherosclerosis and primary hypertriglyceridemia in the women. The lipoprotein composition of this family was investigated with a new methodology that combines gradient ultracentrifugation to isolate lipoprotein subfractions with high-performance liquid chromatography to quantitate apolipoproteins. The major lipoprotein abnormalities that were identified in the hyperlipidemic women in this family were (1) an increased mass of very low density lipoprotein (VLDL) and intermediate density lipoprotein (IDL) with triglyceriderich VLDL but normal IDL composition; (2) triglyceride-rich low-density lipoprotein (LDL) with normal cholesterol and apolipoprotein B concentrations; (3) a relatively normal total mass of high-density lipoprotein (HDL)-L and HDL-M but with a reduction in the apolipoprotein A-I/A-II ratio and a decrease in the cholesterol to triglyceride ratio; (4) an elevation of HDL-D apolipoprotein A-I. The reduction in the apolipoprotein A-I/A-II ratio was also seen in the hyperlipidemic men and in most of nonhyperlipidemic family members and was the most common lipoprotein abnormality that was identified in this family (9 of 11 family members who were not on lipid-lowering medications were affected). The hypertriglyceridemic women appeared to have an increase in the "A-I + A-II" HDL particles in all subfractions and an increase in the "A-I alone" particles in HDL-D. These increases provided the apparently normal total mass of HDL that was observed in these women. These increases in HDL were not seen in the hypertriglyceridemic men. We conclude that a deficiency of the "A-I alone" particle in HDL-L and HDL-M may contribute to the premature atherosclerosis that was seen in this family and that it appears to precede the appearance of hypertriglyceridemia. The increase in the "A-I + A-II" HDL particles did not appear to provide the same protection as would be expected from "A-I alone" HDL.