New reference limits for cardiac troponin T and N-terminal b-type natriuretic propeptide in elders

BACKGROUND AND AIMS

Our aim was to define reference limits for cardiac troponin T (cTnT) and N-terminal pro B-type natriuretic peptide (proBNP) that would better reflect their concentrations in older people. In addition, the incidence of acute myocardial infarctions (AMIs) was studied using these reference limits in an older population with and without previous heart diseases.

MATERIALS AND METHODS

A population-based study with a ten-year follow-up. The reference population was formed by 763 individuals aged over 64 years, with no diagnoses of heart or kidney diseases.

RESULTS

There was a significant increase in cTnT and proBNP concentrations with age. The 99 % reference limits for cTnT were 25 ng/L, 28 ng/l, 38 ng/l, and 71 ng/l for men in five-year-intervals starting from 64 to 69 years to 80 years and older, and 18 ng/L, 22 ng/l, 26 ng/l, and 52 ng/L for women, respectively. The 97.5 % reference limits for proBNP were 272 ng/L, 287 ng/l, 373 ng/l and 686 ng/L for men, and 341 ng/L, 377 ng/l, 471 ng/l, and 794 ng/L for women, respectively. Elevated proBNP was statistically significantly associated with future AMIs in subjects with and without a previous heart disease.

CONCLUSIONS

Age-specific reference limits for cTnT and proBNP are needed to better evaluate cardiac symptoms.

Re-examination of successful agers with lower biological than chronological age still after a 20-year follow-up period

BACKGROUND

Successful ageing is the term often used for depicting exceptional ageing but a uniform definition is lacking. The aim was to re-examine and describe the successful agers living at home at the age of 84 years or over after a 20-year follow-up. The purpose was also to identify possible factors leading to their successful ageing.

METHODS

Successful ageing was defined as the ability to live at home without daily care. Data on the participants' functional ability, objective health, self-rated health and satisfaction with life were gathered at baseline and after a 20-year follow-up period. A measurement of personal biological age (PBA) was established and the difference between the PBA and the chronological age (CA) was counted.

RESULTS

The participants' mean age was 87.6 years (Standard deviation 2.5, range 84-96). All analyzed variables depicted poorer physical ability and subjective health at re-examination than at baseline. Still, 99% of the participants were at least moderately satisfied with their lives. The PBA at baseline was 6.5 years younger than CA, and at re-examination, the difference was even more pronounced at 10.5 years.

DISCUSSION

Even though the participants were chronologically older, had poorer physical ability and subjective health, they were still satisfied with their lives indicating possible psychological resilience. The difference between the PBA and CA was greater at re-examination than at baseline indicating that they were also biologically successful agers.

CONCLUSIONS

Successful agers were satisfied with life despite hardships and had a lower biological than chronological age. Further research is needed to evaluate causality.

Chronic conditions and multimorbidity associated with institutionalization among Finnish community-dwelling older people: an 18-year population-based follow-up study

Aim

The aim of the study is to assess the association of chronic conditions and multimorbidity with institutionalization in older people.

Findings

Having dementia, mood or neurological disorder and/or five or more chronic conditions were associated with a higher risk of institutionalization.

Message

These risk factors should be recognized in primary care when providing and targeting care and support for home-dwelling older people.

Supplementary Information

The online version contains supplementary material available at 10.1007/s41999-021-00535-y.

Purpose

The ageing population is increasingly multimorbid. This challenges health care and elderly services as multimorbidity is associated with institutionalization. Especially dementia increases with age and is the main risk factor for institutionalization. The aim of this study was to assess the association of chronic conditions and multimorbidity with institutionalization in home-dwelling older people, with and without dementia.

Methods

In this prospective study with 18-year follow-up, the data on participants’ chronic conditions were gathered at the baseline examination, and of conditions acquired during the follow-up period from the municipality’s electronic patient record system and national registers. Only participants institutionalized or deceased by the end of the follow-up period were included in this study. Different cut-off-points for multimorbidity were analyzed. Cox regression model was used in the analyses. Death was used as a competing factor.

Results

The mean age of the participants (n = 820) was 74.7 years (64.0‒97.0). During the follow-up, 328 (40%) were institutionalized. Dementia, mood disorders, neurological disorders, and multimorbidity defined as five or more chronic conditions were associated with a higher risk of institutionalization in all the participants. In people without dementia, mood disorders and neurological disorders increased the risk of institutionalization.

Conclusion

Having dementia, mood or neurological disorder and/or five or more chronic conditions were associated with a higher risk of institutionalization. These risk factors should be recognized when providing and targeting care and support for older people still living at home.

Supplementary Information

The online version contains supplementary material available at 10.1007/s41999-021-00535-y.

Subjective and objective health predicting mortality and institutionalization: an 18-year population-based follow-up study among community-dwelling Finnish older adults

BACKGROUND

Objective health measures, such as registered illnesses or frailty, predict mortality and institutionalization in older adults. Also, self-reported assessment of health by simple self-rated health (SRH) has been shown to predict mortality and institutionalization. The aim of this study was to assess the association of objective and subjective health with mortality and institutionalization in Finnish community-dwelling older adults.

METHODS

In this prospective study with 10- and 18-year follow-ups, objective health was measured by registered illnesses and subjective health was evaluated by simple SRH, self-reported walking ability (400 m) and self-reported satisfaction in life. The participants were categorized into four groups according to their objective and subjective health: 1. subjectively and objectively healthy, 2. subjectively healthy and objectively unhealthy, 3. subjectively unhealthy and objectively healthy and 4. subjectively and objectively unhealthy. Cox regression model was used in the analyses. Death was used as a competing factor in the institutionalization analyses.

RESULTS

The mean age of the participants (n = 1259) was 73.5 years (range 64.0-100.0). During the 10- and 18-year follow-ups, 466 (37%) and 877 (70%) died, respectively. In the institutionalization analyses (n = 1106), 162 (15%) and 328 (30%) participants were institutionalized during the 10- and 18-year follow-ups, respectively. In both follow-ups, being subjectively and objectively unhealthy, compared to being subjectively and objectively healthy, was significantly associated with a higher risk of institutionalization in unadjusted models and with death both in unadjusted and adjusted models.

CONCLUSIONS

The categorization of objective and subjective health into four health groups was good at predicting the risk of death during 10- and 18-year follow-ups, and seemed to also predict the risk of institutionalization in the unadjusted models during both follow-ups. Poor subjective health had an additive effect on poor objective health in predicting mortality and could therefore be used as part of an older individual's health evaluation when screening for future adverse outcomes.

Frailty, walking ability and self-rated health in predicting institutionalization: an 18-year follow-up study among Finnish community-dwelling older people

Background

In clinical practice, there is a need for an instrument to screen older people at risk of institutionalization.

Aims

To analyze the association of frailty, walking-ability and self-rated health (SRH) with institutionalization in Finnish community-dwelling older people.

Methods

In this prospective study with 10- and 18-year follow-ups, frailty was assessed using FRAIL Scale (FS) (n = 1087), Frailty Index (FI) (n = 1061) and PRISMA-7 (n = 1055). Walking ability was assessed as self-reported ability to walk 400 m (n = 1101). SRH was assessed by a question of general SRH (n = 1105). Cox regression model was used to analyze the association of the explanatory variables with institutionalization.

Results

The mean age of the participants was 73.0 (range 64.0‒97.0) years. Prevalence of institutionalization was 40.8%. In unadjusted models, frailty was associated with a higher risk of institutionalization by FS in 10-year follow-up, and FI in both follow-ups. Associations by FI persisted after age- and gender-adjustments in both follow-ups. By PRISMA-7, frailty predicted a higher risk of institutionalization in both follow-ups. In unadjusted models, inability to walk 400 m predicted a higher risk of institutionalization in both follow-ups and after adjustments in 10-year follow-up. Poor SRH predicted a higher risk of institutionalization in unadjusted models in both follow-ups and after adjustments in 10-year follow-up.

Discussion

Simple self-reported items of walking ability and SRH seemed to be comparable with frailty indexes in predicting institutionalization among community-dwelling older people in 10-year follow-up.

Conclusions

In clinical practice, self-reported walking ability and SRH could be used to screen those at risk.

Electronic supplementary material

The online version of this article (10.1007/s40520-020-01551-x) contains supplementary material, which is available to authorized users.

A practical laboratory index to predict institutionalization and mortality - an 18-year population-based follow-up study

Background

Previously, several indexes based on a large number of clinical and laboratory tests to predict mortality and frailty have been produced. However, there is still a need for an easily applicable screening tool for every-day clinical practice.

Methods

A prospective study with 10- and 18-year follow-ups. Fourteen common laboratory tests were combined to an index. Cox regression model was used to analyse the association of the laboratory index with institutionalization and mortality.

Results

The mean age of the participants (n = 1153) was 73.6 (SD 6.8, range 64.0–100.0) years. Altogether, 151 (14.8%) and 305 (29.9%) subjects were institutionalized and 422 (36.6%) and 806 (69.9%) subjects deceased during the 10- and 18-year follow-ups, respectively. Higher LI (laboratory index) scores predicted increased mortality. Mortality rates increased as LI scores increased both in unadjusted and in age- and gender-adjusted models during both follow-ups. The LI did not significantly predict institutionalization either during the 10- or 18-year follow-ups.

Conclusions

A practical index based on routine laboratory tests can be used to predict mortality among older people. An LI could be automatically counted from routine laboratory results and thus an easily applicable screening instrument in clinical settings.

Frailty and mortality: an 18-year follow-up study among Finnish community-dwelling older people

BACKGROUND

There is a lack of agreement about applicable instrument to screen frailty in clinical settings.

AIMS

To analyze the association between frailty and mortality in Finnish community-dwelling older people.

METHODS

This was a prospective study with 10- and 18-year follow-ups. Frailty was assessed using FRAIL scale (FS) (n = 1152), Rockwood's frailty index (FI) (n = 1126), and PRISMA-7 (n = 1124). To analyze the association between frailty and mortality, Cox regression model was used.

RESULTS

Prevalence of frailty varied from 2 to 24% based on the index used. In unadjusted models, frailty was associated with higher mortality according to FS (hazard ratio 7.96 [95% confidence interval 5.10-12.41] in 10-year follow-up, and 6.32 [4.17-9.57] in 18-year follow-up) and FI (5.97 [4.13-8.64], and 3.95 [3.16-4.94], respectively) in both follow-ups. Also being pre-frail was associated with higher mortality according to both indexes in both follow-ups (FS 2.19 [1.78-2.69], and 1.69 [1.46-1.96]; FI 1.81[1.25-2.62], and 1.31 [1.07-1.61], respectively). Associations persisted even after adjustments. Also according to PRISMA-7, a binary index (robust or frail), frailty was associated with higher mortality in 10- (4.41 [3.55-5.34]) and 18-year follow-ups (3.78 [3.19-4.49]).

DISCUSSION

Frailty was associated with higher mortality risk according to all three frailty screening instrument used. Simple and fast frailty indexes, FS and PRISMA-7, seemed to be comparable with a multidimensional time-consuming FI in predicting mortality among community-dwelling Finnish older people.

CONCLUSIONS

FS and PRISMA-7 are applicable frailty screening instruments in clinical setting among community-dwelling Finnish older people.

Gender-specific change in leptin concentrations during long-term CPAP therapy

Purpose

Nasal continuous positive airway pressure (CPAP) alleviates sleepiness in patients with obstructive sleep apnoea syndrome (OSAS), but part of OSAS patients keep gaining weight. Leptin and insulin-like growth factor-1 (IGF-1) interact with energy balance, and CPAP therapy has been suggested to influence these endocrine factors. We hypothesised that leptin would decrease during long-term CPAP therapy, and weight gain would associate with OSAS severity, lower CPAP adherence, lower IGF-1, and leptin concentrations.

Methods

Consecutive patients (n = 223) referred to sleep study with suspected OSAS were enrolled. Patients underwent cardiorespiratory polygraphy at baseline. Questionnaires were completed, and blood samples were drawn both at baseline and after 3 years. A total of 149 (67%; M 65, F 84) patients completed the follow-up. Plasma samples were available from 114 patients, 109 of which with CPAP adherence data (49 CPAP users, 60 non-users).

Results

At baseline, the CPAP users were more obese and had more severe OSAS than the non-users. Leptin concentrations did not differ. After follow-up, leptin concentrations were higher in CPAP users (30.2 ng/ml vs. 16.8 ng/ml; p = 0.001). In regression analysis, increase in leptin concentrations was independent of age, baseline body mass index (BMI), or the change in BMI. Leptin concentrations increased among females (− 8.9 vs. 12.7 ng/ml; p < 0.001); whereas in men, CPAP did not have an effect, if not opposed the natural decrease in leptin observed in men not using CPAP. Change in IGF-1 levels did not differ.

Conclusions

Our results suggest increase in leptin concentrations during long-term CPAP therapy among females.

Electronic supplementary material

The online version of this article (10.1007/s11325-019-01846-y) contains supplementary material, which is available to authorized users.

Biomarkers of kidney function and prediction of death from cardiovascular and other causes in the elderly: A 9-year follow-up study

BACKGROUND

Cystatin C is claimed to be superior to creatinine-based estimates of glomerular filtration rate (eGFRcr). The purpose of the study is to analyze whether cystatin C, creatinine, and/or estimated glomerular filtration rates (eGFR) predicted cardiovascular and/or non-cardiovascular deaths among Finnish elderly.

METHODS

Hazard ratios (HR) of cystatin C, creatinine and eGFRs for cardiovascular and non-cardiovascular deaths.

RESULTS

During a 9-year follow-up, 275 died, 192 deaths were a result of cardiovascular disease. In age-adjusted analyses, cystatin C predicted the risk of non-cardiovascular and cardiovascular death in men (HR for 0.1-unit increase 1.12 [95% CI, 1.04-1.19] for non-CVD deaths and 1.18 [1.09-1.28] for CVD deaths) and women (1.14 [1.07-1.21] and 1.14 [1.06-1.22], respectively). CKD-EPIcr-cyc predicted the risk of CVD deaths in men (HR for 5-unit decrease 1.17 [1.09-1.25]) and women (1.09 [1.02-1.17]) and non-CVD deaths in women (1.07 [1.01-1.14]). Also, MDRD (HR for 5-unit decrease 1.16 [1.05-1.27]) and CKD-EPI (HR for 5-unit decrease 1.15 [1.05-1.25]) predicted CVD deaths among men. After additional adjustments, predictive value of cystatin C remained significant. Also, the predictive value of CKD-EPIcr-cys remained significant in non-CVD deaths among women.

CONCLUSION

Cystatin C was clearly the best predictor for cardiovascular and non-cardiovascular deaths among Finnish elderly. Serum cystatin C is more accurate for clinical decision making than creatinine-based eGFR equations or the combined CKD-EPIcr-cys equation in persons older than 64years.

Proton Tl Relaxation Time of Normal and Abnormal Urine

Relaxation times Tl of normal and abnormal urine samples were measured with a 0.02 tesla MRI device in a spectrometric mode. Protein containing urine from patients with glomerulonephritis showed a slight shortening of Tl relaxation time. Radiographic contrast medium, pH, osmolality or glucose in diabetes did not significantly change the Tl relaxation time of urine. Urine can be used as a T1 relaxation reference in MR imaging of the pelvis even if the patient has received radiographic contrast medium or has diabetes or proteinuria for any reason.

Does high sensitive CRP improve cardiovascular risk prediction in metabolic syndrome among the aged?

OBJECTIVES

To analyze whether an elevated level of high hsCRP has an additive effect on metabolic syndrome (MetS) in predicting future cardiovascular events (CVEs) as well as on all-cause mortality among the aged subjects.

DESIGN

A prospective, population-based study with a 9-year follow-up. The study population consisted of persons aged 64 and above in 1998-99 without vascular disease and CRP less than 10 mg/l at baseline (n = 733). Adjusted hazard ratios (HRs) and their 95% confidence intervals (CIs) for CVEs and all-cause mortality predicted by baseline MetS (defined by both International Diabetes Federation (IDF) and World Health Organization (WHO)) and hsCRP-level were estimated.

RESULTS

During the 9-year follow-up, a total of 142 CVEs and 206 deaths occurred. After multivariable adjustment, no significant interactions were found between hsCRP and MetS in CVEs (IDF: p = 0.828; WHO: p = 0.572) or in all-cause mortality (IDF: p = 0.113; WHO: p = 0.374). HsCRP was not associated with the occurrence of CVEs (IDF: HR = 1.10, 95% CI = 0.92-1.32, p = 0.281; WHO: HR = 1.10, 95% CI = 0.93-1.32, p = 0.247) or with all-cause mortality (IDF: HR = 1.12, 95% CI = 0.97-1.29, p = 0.134; WHO: HR = 1.11, 95% CI = 0.96-1.28, p = 0.146).

CONCLUSIONS

It seems that hsCRP does not give any extra value in evaluation of CVE risk or all-cause mortality of older subjects with MetS.

Metabolic syndrome defined by modified International Diabetes Federation criteria and type 2 diabetes mellitus risk: a 9-year follow-up among the aged in Finland

The aim was to analyse the relationship between metabolic syndrome and type 2 diabetes mellitus risk among the aged. This was a prospective population-based study, with a 9-year follow-up. All subjects of the municipality of Lieto in Finland aged ≥64 in 1998-1999 with no type 2 diabetes mellitus at baseline (n=1117) were included. Hazard ratios for incident type 2 diabetes mellitus predicted by metabolic syndrome (defined by modified International Diabetes Federation criteria) were estimated. During the 9-year follow-up, a total of 69 participants (6.2%) developed type 2 diabetes mellitus. After multivariable adjustment (age, gender, smoking, frequency of exercise, cardiovascular disease and low-density lipoprotein-cholesterol), type 2 diabetes mellitus (hazard ratio, 95% confidence interval) (3.15, 1.89-5.25, p < 0.001) was more common in subjects with metabolic syndrome compared to subjects without it. Evaluating metabolic syndrome components individually, impaired fasting glucose (5.09, 2.64-9.82, p < 0.001) and obesity (1.71, 1.05-2.97, p = 0.034) predicted a higher incidence of type 2 diabetes mellitus. Our findings suggest that metabolic syndrome predicts onset of type 2 diabetes mellitus even in late life. Impaired fasting glucose and obesity should be targets for primary prevention of diabetes among the aged with metabolic syndrome.

Circulating oxidised LDL lipids, when proportioned to HDL-c, emerged as a risk factor of all-cause mortality in a population-based survival study

BACKGROUND AND OBJECTIVE

the data concerning the predictive role of oxidised LDL (ox-LDL) in all-cause mortality are scarce. We investigated whether circulating ox-LDL would stand out as a risk factor of total mortality in the elderly. Study subjects, design and methods: a total of 1,260 elderly inhabitants (533 men, 727 women) aged 64 years or more from Lieto, South-Western Finland participated the study in 1998-99. Medical records were re-examined approximately a decade later in January 2009. Circulating ox-LDL lipids were used as the main outcome measure. The comparisons were obtained by the Cox hazard ratio model.

RESULTS

during the 10-year follow-up, 467 participants had died (37%), of whom 36% had died of atherosclerotic cardiovascular diseases. Ox-LDL was a significant predictor of all-cause mortality, when proportioned to low-density lipoprotein cholesterol (LDL-c), high-density lipoprotein cholesterol (HDL-c) or apolipoprotein A1 (apoA1). These findings were independent of age, sex, body mass index, smoking, blood pressure and diabetes (P < 0.05 for all).

CONCLUSION

circulating ox-LDL lipids, when proportioned to LDL-c, HDL-c or apoaA1, stand out as a risk factor for all-cause mortality independent of major confounding attributes. In the prospective survival and increasing disease burden caused by accumulating age, oxidative stress may have a considerable role.

The temporal relationship between growth hormone and slow wave sleep is weaker after menopause

OBJECTIVE

To study the temporal association between growth hormone (GH) and slow wave sleep (SWS) in middle-aged women.

METHODS

Seventeen premenopausal and 18 postmenopausal women were studied using all-night polygraphic sleep recordings and blood sampling at 20-min intervals. The postmenopausal women were re-studied after six months on hormone therapy (HT) according to a randomized, double-blind, placebo-controlled protocol.

RESULTS

The total sleep time (premenopausal 361.9±81.5 min, postmenopausal 358±67.7 min) and the percentages of the sleep stages did not differ between pre- and postmenopausal women. In postmenopausal women the first GH peak after sleep onset occurred later and with a more variable time interval compared to premenopausal women. The percentage of SWS was highest 40-20 min prior to the first GH peak after sleep onset in both groups with a higher SWS proportion in premenopausal women (p=0.048), although the total SWS percent for night did not differ. HT did not affect the distribution of SWS in postmenopausal women.

CONCLUSIONS

The temporal relationship between GH and SWS in premenopausal women is less robust after menopause and is not improved with HT.

Endogenous testosterone and brachial artery endothelial function in middle-aged men with symptoms of late-onset hypogonadism

In aging men, serum endogenous testosterone is inversely associated with common carotid intima-media thickness (IMT) and directly with beneficial plasma lipid levels; however, the relationship to endothelial function is poorly characterized. We examined the association between serum testosterone and endothelium-dependent brachial artery flow-mediated dilatation (FMD) in middle-aged to elderly men. A group of 83 men aged 40?69 years (mean 55.9 ± 7.5 [SD]) with andropausal symptoms were studied. We measured their serum lipids, testosterone, luteinizing hormone, mean carotid IMT and brachial artery FMD by high resolution B-mode ultrasound. Brachial FMD correlated inversely with vessel diameter (r = -0.38, p = 0.0004), alcohol consumption (r = -0.22, p = 0.047) and serum testosterone (r = -0.27, p = 0.01), but not with luteinizing hormone. In multivariate analysis, FMD was explained by testosterone (β = -0.17, p = 0.0226), high density lipoprotein cholesterol (β = 4.17, p = 0.0312) and vessel diameter (β = -4.37, p < 0.0001) when adjusted for age, body mass index, triglycerides, blood pressure, carotid IMT, smoking, alcohol consumption, cardiovascular diseases and use of lipid lowering medication (HMG-CoA reductase inhibitors). In middle-aged to elderly men, there is an inverse correlation between serum testosterone and brachial FMD. These data suggest that testosterone may have an adverse effect on systemic endothelial function.

Metabolic syndrome and vascular risk: a 9-year follow-up among the aged in Finland

The aim was to analyze the relationship between metabolic syndrome (MetS) and vascular risk among the aged. A prospective population-based study, with a 9-year follow-up. All subjects of the municipality of Lieto in Finland aged ≥64 in 1998-99 participated (n = 1183). Hazard ratios (HRs) for fatal or non-fatal coronary (CHD), cerebrovascular (CV), or all vascular events predicted by MetS (defined by International Diabetes Federation) were estimated. During the 9-year follow-up, a total of 348 vascular events occurred, including 208 CHD and 150 CV events. After multivariable adjustment, CHD events (1.70, 1.07-2.71, P = .026) and vascular events (1.57, 1.07-2.30, P = .021) were more common in men with MetS compared to men without it. Evaluating MetS components individually, low HDL-cholesterol among women predicted a higher occurrence of CV (2.44, 1.46-4.09, P < .001) and all vascular (1.78, 1.26-2.53, P = .001) events. Elevated blood pressure among men was related to fewer CHD events (0.46, 0.25-0.83, P = .010). Our findings suggest that MetS does predict vascular events in late life among men. In older women, only low HDL-cholesterol was associated with vascular risk. Slightly or moderately elevated blood pressure values do not predict vascular events in this age group.

Marked decrease in serum HDL cholesterol level during acute myocardial infarction

The concentrations of serum total and HDL cholesterol and triglycerides were determined in 57 patients during the course of AMI. In seven days the concentration of serum cholesterol decreased by 24% and that of HDL cholesterol by 31%. The mean HDL/total cholesterol ratio decreased significantly (p less than 0.01) from 0.163 to 0.145. The magnitude of the change in both HDL and total cholesterol showed a positive correlation with infarction size. The concentration of triglycerides decreased in seven days on the average by 31% but there was great individual variation, which was not dependent on infarction size. Four months after infarction both HDL and total cholesterol as well as triglyceride concentrations had returned to the initial levels. There was a significant negative correlation between the concentrations of HDL cholesterol and triglycerides on admission (r = -0.66) and after four months (r = -0.53) but no correlation after seven days. The results indicate that the determination of serum lipids, including HDL cholesterol, in patients with AMI can, and should be performed on admission to hospital and not at the time of discharge, in order to get reliable estimates of these cardiovascular risk factors.

Serum creatine kinase and lactate dehydrogenase during cardiac irradiation

Thirty patients irradiated to a major part of the heart had serial determinations of serum total creatine kinase (S-CK), creatine kinase subunit B (S-CK-B), total lactate dehydrogenase (S-LD) and lactate dehydrogenase isoenzyme 1 (S-LD-1) activity at the beginning, at the end and 1-4 months after radiotherapy. One patient had an elevated total S-CK activity three months after radiotherapy, but none of the patients had an elevated S-CK-B activity during follow-up. Three patients had elevated serum LD before irradiation, two patients during and two patients after radiotherapy, but only one patient had an elevated S-LD-1 activity, which decreased during irradiation. We conclude that the heart muscle is not injured by cardiac irradiation to such an extent that CK, CK-B, LD and LD-1 activities rise in serum, if moderate doses (39-62 Gy, NSD 1,137-1,775 rets) are delivered to the heart.

Association between markers of renal function and C-reactive protein level in the elderly: confounding by functional status

OBJECTIVE

To analyse the cross-sectional association between measures of renal function and inflammation in an elderly population and to evaluate the confounding effect of impaired physical functioning on these relationships.

MATERIAL AND METHODS

Cystatin C and creatinine were measured in serum samples from 1110 elderly subjects in a community-based cross-sectional survey (Lieto Study) in southwestern Finland. Glomerular filtration rate (GFR) was estimated by means of the Modification of Diet in Renal Disease (MDRD) equation. Associations between renal measures and sensitive C-reactive protein (CRP) and the impact of functional status were determined by multivariate linear models.

RESULTS

Based on standardized coefficients, cystatin C (beta 0.19; p<0.001) showed the strongest association with CRP compared to creatinine (beta 0.14; p<0.001) and estimated GFR (beta -0.13; p<0.001). Levels of CRP linearly increased across quintiles of cystatin C, whereas for creatinine and estimated GFR the increase was less graded. Impaired physical functioning was strongly associated with elevated levels of cystatin C (p<0.001) and CRP (p<0.001), but not with creatinine (p = 0.45) or estimated GFR (p = 0.38). For persons with impaired physical functioning, the odds ratio for belonging to the highest compared to the lowest cystatin C quintile was 7.04 (95% confidence interval 3.49-14.9; p<0.001), whereas for creatinine and estimated GFR this difference was not significant.

CONCLUSION

The weaker association observed between CRP and creatinine-based measures, as compared to cystatin C, reflects the misclassification of elderly frail subjects as having normal kidney function rather than suggests cystatin C itself to be a marker of inflammation.

Long-term follow-up of renal function after high-dose methotrexate treatment in children

BACKGROUND

High-dose methotrexate (HD-MTX) is commonly used in treatment of pediatric leukemias and lymphomas. Transient deterioration in renal function is frequently noted during HD-MTX treatment, but possible long-term changes are less well known. In this study we aimed to study long-term renal prognosis after HD-MTX treatment, and to find possible underlying risk factors for reduced renal function.

PROCEDURE

Medical records of pediatric cancer patients treated with HD-MTX were reviewed retrospectively after follow-up of 1-10 years. Renal function before and after chemotherapy was investigated in a total of 28 patients. Assessment of glomerular and tubular function was prospectively evaluated in each case. Glomerular function was evaluated by either (51)Cr-EDTA or (99m)Tc-DTPA clearance methods, and by urinary albumin excretion. Tubular function was assessed by measuring blood electrolyte levels and urinary alpha(1)- or beta(2)-microglobulin.

RESULTS

A decrease in glomerular filtration rate (GFR) was statistically significant as follow-up time increased (P = 0.02). Age at the time of diagnosis and exposure to potentially nephrotoxic antibiotics during cancer treatment had no influence on GFR. However, albuminuria was observed more often in patients treated with amphotericin B or gentamycin (P = 0.04). No changes in tubular function were observed.

CONCLUSIONS

Our results show that HD-MTX treatment significantly decreases GFR and may cause albuminuria in pediatric cancer patients several years after treatment. Long-term renal follow-up of these patients is therefore important.

24-hour serum levels of growth hormone, prolactin, and cortisol in pre- and postmenopausal women: the effect of combined estrogen and progestin treatment

OBJECTIVE

Our objective was to study the 24-h profiles of GH, prolactin (PRL), and cortisol concentrations in older postmenopausal and middle-aged premenopausal women, before and after estrogen-progestin treatment (EPT).

DESIGN

The study was a randomized, placebo-controlled, double-blind trial. GH, PRL, and cortisol were sampled every 20 min for 24 h in 18 postmenopausal (aged 58-70 yr) and 17 premenopausal (aged 45-51 yr) women before and after 6 months of EPT.

RESULTS

The mean 24-h GH (1.0 vs. 1.8 mU/liter, P = 0.033) and PRL (6.8 vs. 10.0 ng/ml, P = 0.009) concentrations were lower in postmenopausal than in premenopausal women. After EPT, the postmenopausal GH and PRL did not differ from premenopausal baseline levels. Postmenopausal mean 24-h GH (P < 0.001) and PRL (P = 0.002), daytime GH (P < 0.001) and nighttime PRL (P = 0.004) were higher during EPT compared with placebo. Cortisol levels did not differ. Premenopausal mean nighttime PRL (P = 0.026) and cortisol (P = 0.018) were higher during EPT compared with placebo. Postmenopausal PRL and premenopausal GH and PRL concentrations were higher at night than during the day. EPT did not alter this pattern.

CONCLUSIONS

Menopause was associated with decreased 24-h levels of GH and PRL, which were reversible with EPT. In contrast, cortisol levels were not affected by menopause or EPT. In middle-aged premenopausal women, the studied effects of EPT were limited to nighttime increases of PRL and cortisol.

Smoking and low serum testosterone associates with high concentration of oxidized LDL

BACKGROUND

The interplay between smoking, oxidized low-density lipoprotein cholesterol (ox-LDL) and gonadal hormones has been scarcely investigated.

AIM

To investigate associations in ox-LDL and gonadal hormones in smokers and non-smokers

METHODS

Participants (n=164) were obtained from a population cohort of Finnish men aged 40-70 years. The subjects answered a detailed questionnaire on their health behaviour, medication, diseases, and different symptoms, and the hormonal and lipid profiles were measured.

RESULTS

Smokers (n=33) had higher levels of ox-LDL (21%) and more free testosterone (12%) (P<0.01 for all) than non-smokers (n=131). The difference between smokers and non-smokers in ox-LDL persisted after controlling for possible confounding factors. When the smokers were divided into two subgroups (n=16 and n=17) according to total testosterone (< or =15 and >15 nmol/L), the ox-LDL in the low-testosterone subgroup was significantly higher (30%) than in the high-testosterone group (P=0.006). Similarly in the corresponding non-smoking subgroups (n=72 and n=59), ox-LDL was significantly higher (11%) in the low-testosterone subgroup than in the high-testosterone subgroup (P=0.012).

CONCLUSIONS

Smoking men have significantly more ox-LDL than non-smoking men. Furthermore, if smoking is combined with a low serum testosterone, ox-LDL is even higher. This may suggest a higher risk for atherosclerosis.

Discrepancy between total white blood cell counts and serum C-reactive protein levels in febrile children

Total white blood cell (WBC) counts and serum C-reactive protein (CRP) are used as inflammatory markers in febrile children. We studied the occurrence and clinical significance of discrepancy in these markers. From a 2-y period, we retrospectively reviewed the medical records of febrile children (> or =1 month of age) with WBC > or =15 x 10(9)/l and/or CRP levels > or =80 mg/l, as well as of children with lower values in both these parameters. WBC and CRP were discordant in 556 children and concordantly high in 194 children. A severe bacterial disease was presumed in 57% of children with concordantly high WBC and CRP, in 20% of those with discordant values, and in 5% of those with low levels of these markers (p<0.001). Non-streptococcal tonsillitis was the most common viral infection associated with elevated WBC and CRP. In conclusion, WBC and CRP are commonly discrepant in febrile children. Measuring both markers increases substantially the detection rate of bacterial infections.

Endogenous testosterone and serum lipids in middle-aged men

BACKGROUND

The role of decreasing testosterone levels influencing lipid metabolism in aging men is not well established.

METHODS

We studied 1619 40 to 69-year old men with andropausal symptoms, who underwent measurements of serum testosterone, triglycerides, total-, and HDL-cholesterol.

RESULTS

Testosterone (mean 15.25 nmol/l+/-5.43 S.D., range 3.6-45.0 nmol/l) correlated directly with HDL-cholesterol (r=0.24, p<0.0001) and inversely with total cholesterol (r=-0.06, p<0.03), triglycerides (r=-0.30, p<0.0001) and body mass index (r=-0.34, p<0.0001), but not with LDL-cholesterol (r=0.05, p=0.09). In multivariate analyses adjusted for age, body mass index, smoking, alcohol consumption, diabetes and cardiovascular diseases, the significant determinants for serum triglycerides were testosterone (beta=-0.03, p<0.0001), age (beta=-0.01, p<0.0001), body mass index (beta=0.039, p<0.0001) and cardiovascular diseases (beta=0.09, p<0.04). The multivariate correlates of HDL-cholesterol included testosterone (beta=0.007, p<0.0001), body mass index (beta=-0.02, p<0.0001) and alcohol consumption (beta=0.02, p<0.0001).

CONCLUSIONS

We conclude that in aging men low testosterone levels are associated with a potentially atherogenic lipid profile including high triglycerides and low HDL-cholesterol.

Biochemical reference intervals for sex hormones with a new AutoDelfia method in aged men

BACKGROUND

Our aim was to establish sex hormone reference intervals measured with a new AutoDelfia immunoassay method for aged men free of medication and/or conditions known to influence sex hormone levels.

METHODS

The reference population consisted of 466 individuals between 64 and 97 years (mean 72 years) and a mean body mass index (BMI) of 26.9 kg/m(2).

RESULTS AND CONCLUSIONS

Because age correlated significantly with most sex hormones studied, we calculated reference intervals for three age groups (64-69, 70-74 and > or =75 years). In clinical practice, single ranges can be used for men aged 64 years or over for testosterone, estradiol and follicle-stimulating hormone (FSH) with the AutoDelfia method. For free testosterone and luteinizing hormone (LH), separate reference intervals should be used for men aged 64-74 years and those aged 75 years or over. For sex hormone-binding globulin, two separate reference intervals by age (64-69 and > or =70 years) are also needed for aged men. LH and FSH reference ranges should be judged with caution, because they may be too high due to cases of subclinical hypogonadism included in the reference population.

Vitamin B12 deficiency in the aged: a population-based study

BACKGROUND

vitamin B12 deficiency is common in the aged, but it is controversial whether only some risk groups should be investigated instead of screening the entire aged population.

OBJECTIVES

to describe the prevalence of vitamin B12 deficiency in the Finnish aged, and to find out if the subjects especially prone to vitamin B12 deficiency could be identified by the risk factors or clinical correlates.

DESIGN

a cross-sectional, population-based study of 1048 aged subjects (age 65-100 years) was carried out. Data on lifestyle factors and clinical conditions were collected, physical examinations were conducted and laboratory variables related to vitamin B12 were measured.

RESULTS

vitamin B12 deficiency had been previously diagnosed in 27 (2.6%) subjects, and a laboratory diagnosis (total vitamin B12 <150 pmol/l, or total vitamin B12 150-250 pmol/l and holotranscobalamin < or =37 pmol/l and homocysteine > or =15 micromol/l) was made for 97 (9.5%) subjects. Low serum total vitamin B12 (<150 pmol/l) was observed in 6.1% and borderline total vitamin B12 (150-250 pmol/l) in 32% of the subjects. Male gender (OR 1.9, 95% CI 1.2-2.9), age > or =75 (OR 2.2, 95% CI 1.4-3.4) and refraining from milk products (OR 2.3, 95% CI 1.2-4.4) increased the probability for vitamin B12 deficiency. Anaemia (OR 1.3, 95% CI 0.7-2.3) or macrocytosis (OR 1.2, 95% CI 0.6-2.7) did not predict vitamin B12 deficiency.

CONCLUSION

undiagnosed vitamin B12 deficiency is remarkably common in the aged, but no specific risk group for screening can be identified. Thus, biochemical screening of unselected aged population is justified. General practitioners play a key role in diagnosing early vitamin B12 deficiency.

Menopausal estrogen therapy predicts better nocturnal oxyhemoglobin saturation

OBJECTIVES

The respiratory responses in the few previous studies evaluating the effects of short-term unopposed estrogen therapy on breathing in postmenopausal women have been inconsistent. We performed a study to investigate whether long-term estrogen therapy would prevent age-related decline in nocturnal arterial oxyhemoglobin saturation and whether higher serum estradiol concentration is associated with better arterial oxyhemoglobin saturation.

METHODS

Sixty-four healthy postmenopausal women were followed-up for 5 years in a 5-year prospective open follow-up study. The women were users or non-users of estrogen therapy according to their personal preference.

RESULTS

Mean overnight arterial oxyhemoglobin saturation was similar at baseline (94.3 +/- 1.1%) and after follow-up (94.5 +/- 1.6%). Present estrogen users had higher mean arterial oxyhemoglobin saturation (95.2 +/- 1.4%) than present non-users (94.0 +/- 1.5%), when adjusted for age and body mass index (p = 0.042). The change in mean arterial oxyhemoglobin saturation during follow-up was not associated with serum estradiol concentration at baseline but associated with estradiol at follow-up (p = 0.042), when adjusted for age and body mass index. At follow-up, women with higher serum estradiol concentration had also higher mean nocturnal arterial oxyhemoglobin saturation (Pearson r = 0.29, p = 0.019) and lower apnea-hypopnea index (Spearman r = -0.28, p = 0.031). The pooled current estrogen users spent proportionally less time with SaO(2) below 90% than non-users (ANCOVA adjusted for age and BMI, p = 0.017).

CONCLUSIONS

Estrogen use and especially high serum estradiol concentration predict higher mean overnight arterial oxyhemoglobin saturation. The present data suggest that estrogen therapy has favorable respiratory effects.

Effects of health advocacy, counseling, and activation among older coronary heart disease (CHD) patients

BACKGROUND AND AIMS

Coronary heart disease (CHD) is common and the majority of CHD patients are 65 years or older. There exist only a few randomized, controlled intervention studies on secondary prevention of CHD among elderly CHD patients. Our study assessed the effects of health advocacy, counseling, and activation programs with outcome variables of changes in the use of fats, lipid-lowering medications, frequency of exercise, cigarette smoking, serum cholesterol and triglyceride concentrations, blood pressure, and symptoms of late-life CHD among CHD patients of the Lieto Study.

METHODS

Randomized, controlled intervention study. Late-life (> or = 65 yrs) CHD patients were randomized into intervention group (IG) (n = 118) and control group (CG) (n = 109). Intervention consisted of 16 lectures by experts, eight group discussions, six group exercise sessions, and three social activity events.

RESULTS

The use of lipid-lowering medications became more common in IG than in CG among men (p = 0.041), with a similar tendency among women. Among women, decreases in the means of total serum cholesterol (p = 0.009) and LDL-cholesterol (p = 0.049) were greater in IG than in CG.

CONCLUSIONS

The program produced no positive effects on health behavior. Positive effects were gained by the increase in lipid-lowering medications, which reduced mean total serum cholesterol and LDL-cholesterol concentrations. More intensive counseling on health behavior should be planned, implemented, and evaluated.

Does variant luteinizing hormone (V-LH) predispose to improper testicular position in late pregnancy?

Undescended testes are a common urogenital malformation affecting 2-9% of newborn boys. The etiology of cryptorchidism is probably heterogeneous, but insufficient androgen effect has been recognized as one cause of the condition. A common genetic variant (V) form of LH occurs in apparently healthy individuals universally. Compared with wild-type (WT) LH, the V-LH molecule has increased bioactivity in vitro but shorter half-life in vivo. In the present study, we screened 93 cryptorchid (59 uni- and 34 bilateral) and 211 healthy boys for the occurrence of V-LH to evaluate whether it is related to testicular descent. Two immunofluorometric assays with different combinations of MAb, one detecting WT-LH, the other detecting both WT- and V-LH, were used to measure LH concentrations. The ratio of two LH measurements was used to assess the V-LH status. The prevalence of V-LH was similar in the control and cryptorchid groups, and the total prevalence of V-LH corresponded well to the prevalence of V-LH in general Finnish population. Among cryptorchid boys, the prevalence of V-LH was dependent on gestational age: 6.7% at GA <37, 20.9% at GA 37-39, and 42.9% at GA of 40-42 wk. In contrast, the percentage of V-LH status was similar at different gestational ages in all control groups. We conclude that V-LH is not critical for normal testicular descent but the increased prevalence of V-LH among cryptorchid boys with GA >40, suggests that the lower hormonal efficacy of V-LH predisposes for improper testicular descent in late pregnancy.

Acute Prolonged Exercise Reduces Moderately Oxidized LDL in Healthy Men

We studied the effects of a 2-day walk exercise (6 h+6 h) on the serum concentration of circulating moderately oxidized LDL (LDL baseline conjugated dienes), lipids (total cholesterol, LDL cholesterol, HDL cholesterol, and triglyceride), antioxidants (alpha-tocopherol, gamma-tocopherol, beta-carotene, and ubiquinol-10), and antioxidant potential in serum (S-TRAP) and LDL (LDL-TRAP) in healthy well-trained men. The exercise was performed twice with an interval of 14 days. While 6 h walking the subjects drank 6 cl . kg (-1) water which contained either carbohydrate (CHO trial) or placebo (PLA trial). During the 2-day exercise the level of oxidized LDL decreased by 25 % (p=0.001) in the PLA trial. At the same time serum gamma-tocopherol decreased by 20 % (p=0.049), while the other measured antioxidants remained unchanged and the serum antioxidant potential increased by 22 % (p=0.018). Serum total cholesterol decreased by 3 % (p=0.017), serum triglycerides by 22 % (p=0.001), and LDL-cholesterol by 14 % (p=0.045). HDL cholesterol increased by 9 % (p=0.001). The results in the carbohydrate trial were similar to the ones in the PLA trial. The findings suggest that exercise of long duration but of low, non-exhaustive intensity decreases the concentration of circulating oxidized LDL simultaneously with an increase in serum antioxidant potential in healthy trained men. Carbohydrate ingestion during the exercise does not have any further effect on these changes.

Increased carotid atherosclerosis in andropausal middle-aged men

OBJECTIVES

This study examined the association between carotid artery intima-media thickness (IMT), serum sex hormone levels, and andropausal symptoms in middle-aged men.

BACKGROUND

Male sex hormones may play a dual role in the pathogenesis of atherosclerosis in men by carrying both proatherogenic and atheroprotective effects.

METHODS

We studied 239 40- to 70-year-old men (mean +/- SD: 57 +/- 8 years) who participated in the Turku Aging Male Study and underwent serum lipid and sex hormone measurements. Ninety-nine men (age 58 +/- 7 years) were considered andropausal (i.e., serum testosterone <9.8 nmol/l or luteinizing hormone [LH] >6.0 U/l and testosterone in the normal range), and in both situations, they had subjective symptoms of andropause (a high symptom score in questionnaire). Three were excluded because of diabetes. The rest of the men (age 57 +/- 8 years) served as controls. Carotid IMT was determined using high-resolution B-mode ultrasound, and serum testosterone, estradiol (E2), LH, and sex hormone-binding globulin were measured using standard immunoassays.

RESULTS

Andropausal men had a higher maximal IMT compared with controls in the common carotid (1.08 +/- 0.34 vs. 1.00 +/- 0.23, p < 0.05) and in the carotid bulb (1.44 +/- 0.48 vs. 1.27 +/- 0.35, p = 0.003). Common carotid IMT correlated inversely with serum testosterone (p = 0.003) and directly with LH (p = 0.006) in multivariate models adjusted for age, total cholesterol, body mass index, blood pressure, and smoking.

CONCLUSIONS

Middle-aged men with symptoms of andropause, together with absolute or compensated (as reflected by high normal to elevated LH) testosterone deficiency, show increased carotid IMT. These data suggest that normal testosterone levels may offer protection against the development of atherosclerosis in middle-aged men.

Sleep quality, daytime sleepiness and fasting insulin levels in women with chronic obstructive pulmonary disease

STUDY OBJECTIVES

To test the clinical observations that patients with chronic obstructive pulmonary disease (COPD) have impaired sleep quality without excessive daytime sleepiness (EDS), and to analyse the aetiological factors.

PARTICIPANTS

Fifteen non-diabetic postmenopausal women with moderate to severe COPD and 20 community dwelling age-matched control women.

MEASUREMENTS AND RESULTS

Patients completed questionnaires, had a polysomnography and blood tests. Controls filled in the questionnaires. In the Basic Nordic Sleep Questionnaire, the average (+/-sd) scores for sleepiness (9.9+/-3.0 in patients vs. 7.6+/-3.2 in controls, P = 0.025, test range 4-20) and insomnia (18.3+/-3.4 vs. 16.6+/-4.4, P = 123, test range 7-35) were low. Although 53% had a good night's sleep seldom or never and 70% slept restlessly, only 33% felt tired in the mornings. Controls reported better sleep quality, less tiredness and sleepiness. With polysomnography, the total sleep time was 4h 41 min +/-1h 20 min in patients. Sleep was fragmented, the proportion of stage 1 sleep high and rapid eye movement (REM) latency delayed. Sleepiness correlated with fasting serum insulin levels (r = 0.59, P = 0.027) and body movements (r = 0.52, P = 0.047). In stepwise linear regression analyses, sleepiness was positively associated with insulin levels (P = 0.025) but not with body movements. Insulin explained 38.0% of the variance in the sleepiness score, when adjusted for body mass index (BMI).

CONCLUSIONS

Despite short and fragmented sleep, non-diabetic patients with COPD did not have marked EDS. An association between fasting insulin and sleepiness suggests that insulin resistance is involved in EDS.

The effect of thyroid antibody positivity on reference intervals for thyroid stimulating hormone (TSH) and free thyroxine (FT4) in an aged population

Our aims were: 1) to analyze the effect of the methodology used to derive clinically feasible cut-off values for thyroid peroxidase antibodies (TPOAb) and thyroglobulin antibodies (TgAb), which exhibit highly skewed distributions; and 2) to describe the influence of thyroid antibodies on thyroid stimulating hormone (TSH) and free thyroxine (FT

Renal impairment associated with diabetes in the elderly

OBJECTIVE

To characterize renal impairment associated with diabetes in older adults by serum markers of glomerular filtration rate and microalbuminuria tests.

RESEARCH DESIGN AND METHODS

The study population consisted of 187 diabetic and 1,073 nondiabetic subjects (age range 64-100 years) participating in a cross-sectional, population-based survey in southwestern Finland. Renal function was estimated by serum cystatin C (Cys C), serum creatinine (Cr), and the urinary albumin-to-creatinine ratio, and determinants of elevated levels were assessed by multivariate analysis.

RESULTS

Diabetes, compared to hypertension, was a more powerful determinant of elevated Cys C and Cr levels in the very old (age >or=80 years), whereas the impact of hypertension was more pronounced in the younger group (age <80 years). The prevalence of microalbuminuria among diabetic subjects was 29.7%, and 15% had elevated Cr levels, whereas the prevalence of elevated Cys C levels varied considerably depending on whether adult or age-adjusted reference limits were used (64.7 vs. 21.4%). In 64.1% of diabetic subjects with elevated Cys C levels based on age-adjusted reference limits and in 48.2% of subjects with elevated Cr levels, microalbuminuria was absent.

CONCLUSIONS

The impact of diabetes on renal impairment changes with increasing age. Serum markers of glomerular filtration rate and microalbuminuria identify renal impairment in different segments of the diabetic population, indicating that serum markers as well as microalbuminuria tests should be used in screening for nephropathy in diabetic older people. The appropriate reference limit for Cys C in geriatric clinical practice must be defined by further research.

Estimation of glomerular filtration rate in the elderly: a comparison of creatinine-based formulae with serum cystatin C

OBJECTIVES

To estimate the prevalence of decreased kidney function in an elderly population and to evaluate the impact of using alternative markers of glomerular filtration rate (GFR), focusing on serum cystatin C (Cys C) and the Modification of Diet in Renal Disease (MDRD) Study prediction equation.

DESIGN AND METHODS

In a cross-sectional community-based survey renal function was assessed by serum creatinine (SCreat), Cys C and GFR predicted by the Cockcroft-Gault (CG) and the MDRD Study formulae. Associations with age, gender and proteinuria were analysed by linear models.

SUBJECTS

A total of 1246 elderly residents in Lieto, Finland, 64-100 years of age.

RESULTS

The prevalence of moderately or severely decreased renal function, estimated by the MDRD Study equation, was 35.7%; the CG formula yielded 58.6%. The profile of Cys C performance, including variation across age groups and level of health status, showed greater similarity to GFR estimated using the MDRD Study equation than to SCreat alone, or GFR estimated using the CG formula. Discordance between high Cys C levels and only mildly decreased GFR estimates was observed in subjects with functional limitations. Microalbuminuria was associated with Cys C levels only (P =0.047).

CONCLUSION

Prevalence estimates of decreased renal function amongst the elderly vary considerably depending on prediction formula used. Variation in creatinine metabolism amongst elderly comorbid patients and the critical dependence on the SCreat assay and exact calibration, make the use of creatinine-based formulae to predict GFR questionable in geriatric clinical practice. In this setting, Cys C is a promising alternative.

Breathing during sleep in menopause: a randomized, controlled, crossover trial with estrogen therapy

OBJECTIVE

To evaluate the prevalence of different types of nocturnal breathing abnormalities in postmenopausal women and the effect of estrogen replacement therapy (ERT) on nocturnal breathing.

METHODS

A prospective, randomized, placebo-controlled, double-blind, crossover study was completed by 62 of 71 recruited healthy women. The first 3-month treatment period with either estrogen or placebo was followed by placebo washout for a month and then by a second treatment period with crossover to either estrogen or placebo. On a night after each treatment period, sleep was monitored with polysomnography, and breathing was assessed with a static-charge-sensitive bed and oximeter. For the respiratory variables, a sample size of 48 subjects was sufficient to give statistical power of 85% with a significance level of P <.05.

RESULTS

The occurrence of obstructive sleep apnea in all women was low (1.6%), but partial upper airway obstruction, manifesting as an increased respiratory resistance pattern, was more common (17.7%). Estrogen replacement therapy decreased the occurrence (P =.047) and frequency (P =.049) of sleep apnea but had no effect on partial upper airway obstruction or arterial oxyhemoglobin saturation.

CONCLUSION

Partial upper airway obstruction is the most prevalent form of sleep-disordered breathing, occurring ten times more frequently than sleep apnea in postmenopausal women. Unopposed estrogen replacement therapy has only a minor effect on sleep apnea and has no effect on partial airway obstruction.