Secondary hyperparathyroidism: Predictors and relationship with vitamin D status, bone turnover markers and bone mineral density

INTRODUCTION

Secondary hyperparathyroidism (SHPT) has adverse implications for bone health but is relatively understudied. In this study we examine the prevalence and determinants of SHPT and describe the relationship of SHPT with bone turnover markers and bone mineral density (BMD) in older Irish adults.

METHOD

Eligible participants (n = 4139) were identified from the Trinity-Ulster-Department of Agriculture (TUDA) study, a cohort of Irish adults aged ≥60 years. Exclusion criteria included an estimated glomerular filtration rate (eGFR) <30 ml/min and serum calcium >2.5 mmol/l to remove hyperparathyroidism due to advanced chronic kidney disease (CKD) and primary hyperparathyroidism respectively. The relationship between SHPT and bone turnover markers and BMD (measured by densitometry) was examined in a subsample (n = 1488). Vitamin D deficiency was defined as 25-hydroxyvitamin D [25 (OH)D] <30 nmol/l.

RESULTS

Participants had a mean age of 73.6 ± 7.9 years, 65.1 % were female and 19.4 % were found to be vitamin D deficient. The prevalence of SHPT decreased as vitamin D increased, from 30.6 % in those deficient to 9.8 % in those with 25(OH)D ≥ 50 nmol/l and increased with declining kidney function. In non‑calcium supplement users, principal determinants of SHPT were vitamin D deficiency (OR 4.18, CI 3.05-5.73, p < 0.001), eGFR 30-44 ml/min (OR 3.69, CI 2.44-5.57, p < 0.001), loop diuretic use (OR 3.52, CI 2.59-4.79, p < 0.001) and to a lesser extent body mass index (p = 0.001), eGFR 45-59 ml/min (p < 0.001) and 25(OH)D level 30-49 nmol/l (p = 0.002). Similar findings were observed in calcium supplement users, though proton pump inhibitors were also associated with SHPT (OR 1.55, CI 1.08-2.22, p = 0.018) while vitamin D 30-49 nmol/l was not. In participants with SHPT versus those without, bone turnover markers were higher: bone alkaline phosphatase (p = 0.017) and tartrate-resistant acid phosphatase (p = 0.033), whilst there was lower BMD at the neck of femur (0.880 vs. 0.903 g/cm2, p = 0.033) and total hip (0.968 vs. 0.995 g/cm2, P = 0.017).

DISCUSSION

The results show that up to one in six older Irish adults had SHPT and this was associated with lower BMD and higher concentrations of bone turnover markers. Both vitamin D deficiency and 25(OH)D level 30-49 nmol/l were important predictors of SHPT. Loop diuretics and PPIs may also increase the risk of SHPT, and their use may need to be carefully considered in this population. Further studies examining the potential impact of these factors on bone health in similar populations to our study sample are warranted.

Low-Grade systemic inflammation is associated with domain-specific cognitive performance and cognitive decline in older adults: Data from the TUDA study

Studies examining the relationships between chronic inflammation, cognitive function and cognitive decline in older adults have yielded conflicting results. In a large cohort of older adults free from established dementia (n = 3270; 73.1 ± 7.9 years; 68.4% female), we evaluated the cross-sectional and longitudinal relationships between serum cytokines (IL-6, IL-10, TNF-α) and both global and domain-specific cognitive performance (Repeatable Battery for Assessment of Neuropsychological Status [RBANS]). Higher IL-6 (OR: 1.33; 1.06, 1.66, p = 0.01), TNF-α (OR: 1.35; 1.09, 1.67, p = 0.01) and IL-6:IL-10 Ratio (OR: 1.43; 1.17, 1.74, p = 0.001) were cross-sectionally associated with impaired global RBANS performance. For specific cognitive domains, greatest effect sizes were observed between higher TNF-α levels and poorer visual-spatial and attention performance. In a subset of participants (n = 725; 69.8 ± 5.5 years; 67.0% female) with repeat assessment performed at a median of 5.4 years, only higher baseline IL-6:IL-10 ratio was associated with impaired incident overall, immediate memory and visual-spatial performance. Associations were stronger in females, but not modified by age or APOE genotype.

The association between proton pump inhibitors and hyperparathyroidism: a potential mechanism for increased fracture-results of a large observational cohort study

Proton pump inhibitors (PPIs) are associated with increased risk of osteoporotic fracture; however, the mechanism is unclear. PPI users taking calcium supplements were more likely to have hyperparathyroidism compared to non-users (OR 1.56, CI 1.08-2.23, p = 0.018). This highlights the importance of monitoring PPI use, especially in older adults.

PURPOSE

Proton pump inhibitors (PPIs) are associated with increased risk of osteoporotic fracture. Hyperparathyroidism may be implicated, but few studies have considered this relationship. This study evaluated the relationship between PPI use and hyperparathyroidism in older adults.

METHODS

Participants were from the TUDA study, a large cross-sectional cohort of older Irish adults. Participants with an estimated glomerular filtration rate (eGFR) < 30 ml/min and serum calcium > 2.5 mmol/l were excluded to avoid hyperparathyroidism due to chronic renal disease and primary hyperparathyroidism. Hyperparathyroidism was defined as a parathyroid hormone (PTH) > 65 pg/ml. Multivariate regression models were used to analyse the relationship between PPI use and hyperparathyroidism.

RESULTS

A total of 4139 participants met the inclusion criteria, of whom 37.8% (n = 1563) were taking PPI medication. PPI use was identified in 41.4% of calcium supplement users and 35.4% of non-calcium supplement users. Overall, compared to non-users of PPIs, those taking PPIs were older (74.8 vs 72.9 years, p < 0.001) and had a higher prevalence of hyperparathyroidism (17.8 vs 11.0%, p < 0.001). In those taking calcium supplements (but not in non-users), PPI use was significantly associated with hyperparathyroidism (OR 1.56, CI 1.08-2.23, p = 0.018) after adjusting for age, sex, body mass index, serum vitamin D, eGFR, timed-up-and-go, dairy intake, medications, and comorbidities.

DISCUSSION

The results are consistent with the hypothesis of PPIs reducing calcium absorption, leading to a rise in PTH which could mediate increased fracture risk. No relationship of PPI use with hyperparathyroidism was observed in non-users of calcium supplements, possibly owing to lower dietary calcium intake. These results highlight the importance of monitoring PPI use, especially in older adults at risk of fracture.

A 2-Year Randomized Controlled Trial With Low-Dose B-Vitamin Supplementation Shows Benefits on Bone Mineral Density in Adults With Lower B12 Status

Folate, vitamins B12, B6, and riboflavin are required for one-carbon metabolism and may affect bone health, but no previous randomized trial has investigated all four nutrients in this context. We investigated the effect of low-dose B-vitamins for 2 years on bone mineral density (BMD) in a dual-centered, 2-year randomized controlled trial (RCT) in adults aged ≥50 years. Eligible participants not consuming B-vitamin supplements or fortified foods >4 times weekly were randomized to receive daily either combined folic acid (200 μg), vitamin B12 (10 μg), vitamin B6 (10 mg), and riboflavin (5 mg), or "active" placebo, whereby both the intervention and placebo groups received vitamin D (10 μg). BMD was assessed before and after intervention using dual-energy X-ray absorptiometry (DXA) scanning of the total hip, femoral neck, and lumbar spine (L1 to L4). Of 205 eligible participants randomized, 167 completed the trial in full. B-vitamin intervention resulted in increases in serum folate (p < 0.001), serum B12 (p < 0.001), and plasma pyridoxal-5-phosphate (p < 0.001) and decreases in functional biomarkers of B-vitamin status, erythrocyte glutathione reductase activation coefficient (p < 0.001), serum methylmalonic acid (MMA; p < 0.001), and serum total homocysteine (p < 0.001). B-vitamin intervention had no overall effect on BMD, which declined in both treatment groups by approximately 1% (ranging from -0.7% to -1.4%). However, in participants with lower baseline B12 status (serum B12 <246 pmol/L or MMA ≥0.22 μmol/L), B-vitamin intervention reduced the 2-year BMD decline versus placebo: adjusted mean (95% confidence interval [CI]) change of -0.003 (-0.008, 0.002) versus -0.015 (-0.021, -0.010) g/cm² at the total hip and -0.004 (-0.010, 0.001) versus -0.013 (-0.018, -0.007) g/cm² at the femoral neck. In conclusion, the findings indicate that although low-dose B-vitamin intervention for 2 years had no overall effect on BMD, improving B-vitamin status appears to have specific benefits for bone health in adults with lower B12 status. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Vitamin B-6 and riboflavin, their metabolic interaction, and relationship with MTHFR genotype in adults aged 18-102 years

BACKGROUND

The generation of the active form of vitamin B-6, pyridoxal 5'-phosphate (PLP), in tissues is dependent upon riboflavin as flavin mononucleotide, but whether this interaction is important for maintaining vitamin B-6 status is unclear.

OBJECTIVE

To investigate vitamin B-6 and riboflavin status, their metabolic interaction, and relationship with methylenetetrahydrofolate reductase (MTHFR) genotype in adulthood.

METHODS

Data from 5612 adults aged 18-102 y were drawn from the Irish National Adult Nutrition Survey (NANS; population-based sample) and the Trinity-Ulster Department of Agriculture (TUDA) and Genovit cohorts (volunteer samples). Plasma PLP and erythrocyte glutathione reductase activation coefficient (EGRac), as a functional indicator of riboflavin, were determined.

RESULTS

Older (≥65 y) compared with younger (<65 y) adults had significantly lower PLP concentrations (P < 0.001). A stepwise decrease in plasma PLP was observed across riboflavin categories, from optimal (EGRac ≤1.26), to suboptimal (EGRac: 1.27-1.39), to deficient (EGRac ≥1.40) status, an effect most pronounced in older adults (mean ± SEM: 76.4 ± 0.9 vs 65.0 ± 1.1 vs 55.4 ± 1.2 nmol/L; P < 0.001). In individuals with the variant MTHFR 677TT genotype combined with riboflavin deficiency, compared with non-TT (CC/CT) genotype participants with sufficient riboflavin, we observed PLP concentrations of 52.1 ± 2.9 compared with 76.8 ±0.7 nmol/L (P < 0.001). In participants with available dietary data (i.e., NANS cohort, n = 936), PLP was associated with vitamin B-6 intake (nonstandardized regression coefficient β: 2.49; 95% CI 1.75, 3.24; P < 0.001), supplement use (β: 81.72; 95% CI: 66.01, 97.43; P < 0.001), fortified food (β: 12.49; 95% CI: 2.08, 22.91; P = 0.019), and EGRac (β: -65.81; 95% CI: -99.08, -32.54; P < 0.001), along with BMI (β: -1.81; 95% CI: -3.31, -0.30; P = 0.019).

CONCLUSIONS

These results are consistent with the known metabolic dependency of PLP on flavin mononucleotide (FMN) and suggest that riboflavin may be the limiting nutrient for maintaining vitamin B-6 status, particularly in individuals with the MTHFR 677TT genotype. Randomized trials are necessary to investigate the PLP response to riboflavin intervention within the dietary range. The TUDA study and the NANS are registered at www.ClinicalTrials.gov as NCT02664584 (27 January 2016) and NCT03374748 (15 December 2017), respectively.Clinical Trial Registry details: Trinity-Ulster-Department of Agriculture (TUDA) study, ClinicalTrials.gov no. NCT02664584 (January 27th 2016); National Adult Nutrition Survey (NANS), ClinicalTrials.gov no. NCT03374748 (December 15th 2017).

Impact of the MTHFR C677T polymorphism on blood pressure and related central hemodynamic parameters in healthy adults

BACKGROUND

The C677T polymorphism in the gene encoding methylenetetrahydrofolate reductase (MTHFR) is associated with an increased risk of hypertension and cardiovascular disease. Riboflavin, the MTHFR cofactor, is an important modulator of blood pressure (BP) in adults homozygous for this polymorphism (TT genotype). The effect of this genetic variant on BP and related central hemodynamic parameters in healthy adults has not been previously investigated and was examined in this study.

METHODOLOGY

Brachial BP, central BP and pulse wave velocity (PWV; SphygmoCor® XCEL) were measured in adults 18-65 years pre-screened for MTHFR genotype. Riboflavin status was assessed using the erythrocyte glutathione reductase activation coefficient (EGRac) assay.

RESULTS

242 adults with the MTHFR 677TT genotype and age-matched non-TT (CC/CT) genotype controls were identified from a total cohort of 2,546 adults pre-screened for MTHFR genotype. The TT genotype was found to be an independent determinant of hypertension (P=0.010), along with low riboflavin status (P=0.002). Brachial systolic and diastolic BP were higher in TT v non-TT adults by 5.5±1.2 mmHg and 2.4±0.9 mmHg, respectively (both P<0.001). A stronger phenotype was observed in females, with an almost 10 mmHg difference in mean systolic BP in TT v non-TT genotype groups: 134.9 (95% CI 132.1-137.6) vs 125.2 (95% CI 122.3-128.0) mmHg; P<0.001. In addition, PWV was faster in women with the TT genotype (P=0.043).

CONCLUSION

This study provides the first evidence that brachial and central BP are significantly higher in adults with the variant MTHFR 677TT genotype, and that the BP phenotype is more pronounced in females. This article is protected by copyright. All rights reserved.

Reduced kidney function is associated with poorer domain-specific cognitive performance in community-dwelling older adults

OBJECTIVES

Whilst chronic kidney disease has been associated with cognitive impairment, the association between reduced estimated Glomerular Filtration Rate (eGFR) and domain-specific cognitive performance is less clear and may represent an important target for the promotion of optimal brain health in older adults.

METHODS

Participants aged >60 years from the Trinity-Ulster-Department of Agriculture study underwent detailed cognitive assessment using the Mini-Mental State Examination (Mini-Mental State Examination (MMSE)), Frontal Assessment Battery (FAB) and Repeatable Battery for Assessment of Neuropsychological Status (RBANS). Poisson and linear regression models assessed the relationship between eGFR strata and cognitive performance.

RESULTS

In 4887 older adults (73.9 ± 8.3 years; 67.7% female), declining eGFR strata was associated with greater likelihood of error on the MMSE/FAB and poorer overall performance on the RBANS. Following robust covariate adjustment, findings were greatest for GFR <45 ml/ml/1.73 m² (Incidence Rate Ratio: 1.17; 95% CI 1.08, 1.27; p < 0.001 for MMSE; IRR: 1.13; 95% CI 1.04, 1.13; p < 0.001 for FAB; β: -3.66; 95% CI -5.64, -1.86; p < 0.001 for RBANS). Additionally, eGFR <45 ml/ml/1.73 m² was associated with poorer performance on all five RBANS domains, with greatest effect sizes for immediate memory, delayed memory and attention. Associations were strongest in those aged 60-70, with no associations observed in those >80 years.

CONCLUSIONS

Reduced kidney function was associated with poorer global and domain-specific neuropsychological performance. Associations were strongest with eGFR <45 ml/min/1.73 m² and in those aged 60-70 years, suggesting that this population may potentially benefit from potential multi-domain interventions aimed at promoting optimal brain health in older adults.

Glycated haemoglobin (HbA1c ), diabetes and neuropsychological performance in community-dwelling older adults

AIMS

Given that diabetes is associated with cognitive impairment and dementia in later life, we aimed to investigate the relationship between glycated haemoglobin (HbA_1c ), diabetes and domain-specific neuropsychological performance in older adults.

METHODS

Cross-sectional cohort study using data from the Trinity-Ulster-Department of Agriculture (TUDA) study. Participants underwent detailed cognitive and neuropsychological assessment using the Mini-Mental State Examination (MMSE), Frontal Assessment Battery (FAB) and Repeatable Assessment for Neuropsychological Status (RBANS). Linear regression was used to assess associations between HbA_1c , diabetes status and neuropsychological performance, with adjustment for important clinical covariates.

RESULTS

Of 4938 older adults (74.1 ± 8.3 years; 66.9% female), 16.3% (n = 803) had diabetes (HbA_1c  ≥ 6.5%; 48 mmol/mol), with prediabetes (HbA_1c  ≥ 5.7%-6.4%; 39-47 mmol/mol) present in 28.3% (n = 1395). Increasing HbA_1c concentration was associated with poorer overall performance on the FAB [β: -0.01 (-0.02, -0.00); p = 0.04 per % increase] and RBANS [β = -0.66 (-1.19, -0.13); p = 0.02 per % increase]. Increasing HbA_1c was also associated with poorer performance on immediate memory, visuo-spatial, language and attention RBANS domains. Diabetes was associated poorer performance on neuropsychological tests of immediate memory, language, visual-spatial and attention.

CONCLUSIONS

Both increasing HbA_1c and the presence of diabetes were associated with poorer cognitive and domain-specific performance in older adults. HbA_1c , and not just diabetes status per se, may represent an important target in the promotion of optimal brain health in older adults.

Long-term anticholinergic, benzodiazepine and Z-drug use in community-dwelling older adults: What is the impact on cognitive and neuropsychological performance?

BACKGROUND

Long-term use of anticholinergics, benzodiazepines and related drugs (or "Z-drugs") have been associated with cognitive impairment and dementia. However, the relationship of these medications with cognitive function and domain-specific neuropsychological performance in older adults without dementia, is unclear.

METHODS

5135 older adults (74.0 ± 8.3 years; 67.4% female) without a diagnosis of dementia were recruited in Ireland to the Trinity-Ulster-Department of Agriculture (TUDA) study. Detailed cognitive and neuropsychological assessment was conducted using the Mini-Mental State Examination (MMSE), Frontal Assessment Battery (FAB) and Repeatable Battery for Assessment of Neuropsychological Status (RBANS).

RESULTS

A total of 44% (2259 of 5153) used either a potential or definite anticholinergic medication. Overall, 9.7% (n = 500) used a definite anticholinergic medication. Regular benzodiazepine use was reported by 7% (n = 363), whilst 7.5% (n = 387) used a "Z-drug". Use of definite, but not potential anticholinergic medication was associated with poorer performance on all three assessments (β: -0.09; 95% CI: -0.14, -0.03, p = 0.002 for MMSE; β: -0.04; 95% CI: -0.06, -0.02; p < 0.001 for FAB; β: -4.15; 95% CI: -5.64, -2.66; p < 0.001 for RBANS) in addition to all domains of the RBANS. Regular benzodiazepine use was also associated with poorer neuropsychological test performance, especially in Immediate Memory (β: -4.98; 95% CI: -6.81, -3.15; p < 0.001) and Attention (β: -6.81; 95% CI: -8.60, -5.03; p < 0.001) RBANS domains.

CONCLUSIONS

Regular use of definite anticholinergic medications and benzodiazepines, but not potential anticholinergics or "Z-drugs", was associated with poorer overall and domain-specific neuropsychological performance in older adults.

Associations of atrophic gastritis and proton-pump inhibitor drug use with vitamin B-12 status, and the impact of fortified foods, in older adults

BACKGROUND

Atrophic gastritis (AG) and use of proton pump inhibitors (PPIs) result in gastric acid suppression that can impair the absorption of vitamin B-12 from foods. The crystalline vitamin B-12 form, found in fortified foods, does not require gastric acid for its absorption and could thus be beneficial for older adults with hypochlorhydria, but evidence is lacking.

OBJECTIVES

To investigate associations of AG and PPI use with vitamin B-12 status, and the potential protective role of fortified foods, in older adults.

METHODS

Eligible participants (n = 3299) not using vitamin B-12 supplements were drawn from the Trinity-Ulster and Department of Agriculture cohort, a study of noninstitutionalized adults aged ≥60 y and recruited in 2008-2012. Vitamin B-12 status was measured using 4 biomarkers, and vitamin B-12 deficiency was defined as a combined indicator value < -0.5. A pepsinogen I:II ratio <3 was considered indicative of AG.

RESULTS

AG was identified in 15% of participants and associated with significantly lower serum total vitamin B-12 (P < 0.001) and plasma holotranscobalamin (holoTC; P < 0.001), and higher prevalence of vitamin B-12 deficiency (38%), compared with PPI users (21%) and controls (without AG and nonusers of PPIs; 15%; P < 0.001). PPI drugs were used (≥6 mo) by 37% of participants and were associated with lower holoTC concentrations, but only in participants taking higher doses (≥30 mg/d). Regular, compared with nonregular, consumption of fortified foods (i.e., ≥5 and 0-4 portions/wk, respectively) was associated with higher vitamin B-12 biomarkers in all participants, but inadequate to restore normal vitamin B-12 status in those with AG.

CONCLUSIONS

Older adults who have AG and/or use higher doses of PPIs are more likely to have indicators of vitamin B-12 deficiency. Fortified foods, if consumed regularly, were associated with enhanced vitamin B-12 status, but higher levels of added vitamin B-12 than currently provided could be warranted to optimize status in people with AG.

Reliability of Addenbrooke's Cognitive Examination III in differentiating between dementia, mild cognitive impairment and older adults who have not reported cognitive problems

Diagnosing dementia can be challenging for clinicians, given the array of factors that contribute to changes in cognitive function. The Addenbrooke’s Cognitive Examination III (ACE-III) is commonly used in dementia assessments, covering the domains of attention, memory, fluency, visuospatial and language. This study aims to (1) assess the reliability of ACE-III to differentiate between dementia, mild cognitive impairment (MCI) and controls and (2) establish whether the ACE-III is useful for diagnosing dementia subtypes. Client records from the Northern Health and Social Care Trust (NHSCT) Memory Service (n = 2,331, 2013–2019) were used in the analysis including people diagnosed with Alzheimer’s disease (n = 637), vascular dementia (n = 252), mixed dementia (n = 490), MCI (n = 920) and controls (n = 32). There were significant differences in total ACE-III and subdomain scores between people with dementia, MCI and controls (p < 0.05 for all), with little overlap between distribution of total ACE-III scores (< 39%) between groups. The distribution of total ACE-III and subdomain scores across all dementias were similar. There were significant differences in scores for attention, memory and fluency between Alzheimer’s disease and mixed dementia, and for visuospatial and language between Alzheimer’s disease–vascular dementia (p < 0.05 for all). However, despite the significant differences across these subdomains, there was a high degree of overlap between these scores (> 73%) and thus the differences are not clinically relevant. The results suggest that ACE-III is a useful tool for discriminating between dementia, MCI and controls, but it is not reliable for discriminating between dementia subtypes. Nonetheless, the ACE-III is still a reliable tool for clinicians that can assist in making a dementia diagnosis in combination with other factors at assessment.

Impact of the common MTHFR 677C→T polymorphism on blood pressure in adulthood and role of riboflavin in modifying the genetic risk of hypertension: evidence from the JINGO project

BACKGROUND

Genome-wide and clinical studies have linked the 677C→T polymorphism in the gene encoding methylenetetrahydrofolate reductase (MTHFR) with hypertension, whilst limited evidence shows that intervention with riboflavin (i.e. the MTHFR co-factor) can lower blood pressure (BP) in hypertensive patients with the variant MTHFR 677TT genotype. We investigated the impact of this common polymorphism on BP throughout adulthood and hypothesised that riboflavin status would modulate the genetic risk of hypertension.

METHODS

Observational data on 6076 adults of 18-102 years were drawn from the Joint Irish Nutrigenomics Organisation project, comprising the Trinity-Ulster Department of Agriculture (TUDA; volunteer sample) and the National Adult Nutrition Survey (NANS; population-based sample) cohorts. Participants were recruited from the Republic of Ireland and Northern Ireland (UK) in 2008-2012 using standardised methods.

RESULTS

The variant MTHFR 677TT genotype was identified in 12% of adults. From 18 to 70 years, this genotype was associated with an increased risk of hypertension (i.e. systolic BP ≥ 140 and/or a diastolic BP ≥ 90 mmHg): odds ratio (OR) 1.42, 95% confidence interval (CI) 1.07 to 1.90; P = 0.016, after adjustment for antihypertensive drug use and other significant factors, namely, age, male sex, BMI, alcohol and total cholesterol. Low or deficient biomarker status of riboflavin (observed in 30.2% and 30.0% of participants, respectively) exacerbated the genetic risk of hypertension, with a 3-fold increased risk for the TT genotype in combination with deficient riboflavin status (OR 3.00, 95% CI, 1.34-6.68; P = 0.007) relative to the CC genotype combined with normal riboflavin status. Up to 65 years, we observed poorer BP control rates on antihypertensive treatment in participants with the TT genotype (30%) compared to those without this variant, CT (37%) and CC (45%) genotypes (P < 0.027).

CONCLUSIONS

The MTHFR 677TT genotype is associated with higher BP independently of homocysteine and predisposes adults to an increased risk of hypertension and poorer BP control with antihypertensive treatment, whilst better riboflavin status is associated with a reduced genetic risk. Riboflavin intervention may thus offer a personalised approach to prevent the onset of hypertension in adults with the TT genotype; however, this requires confirmation in a randomised trial in non-hypertensive adults.

Riboflavin Is an Important Determinant of Vitamin B-6 Status in Healthy Adults

BACKGROUND

Riboflavin is required to generate the active form of vitamin B-6 (pyridoxal 5'-phosphate; PLP) in tissues, but the relevance of this metabolic interaction for nutritional status of vitamin B-6 is unclear because riboflavin biomarkers are rarely measured in human studies.

OBJECTIVES

The purpose of this study was to identify the determinants of biomarkers of vitamin B-6 and riboflavin status and to examine the relationship between these nutrients in healthy adults.

METHODS

Multiple linear regression was performed on observational data in 407 healthy adults aged 18-92 y who did not use B-vitamin supplements. Vitamin B-6 status was assessed by plasma PLP concentrations and erythrocyte glutathione reductase activation coefficient (EGRac) was used as a functional indicator of riboflavin status.

RESULTS

Dietary intakes of vitamin B-6 and riboflavin were below the average requirements in 10% and 29% of participants, respectively. Suboptimal status of vitamin B-6 (PLP ≤30.0 nmol/L) was more prevalent in adults aged ≥60 y than in younger participants (i.e., 14% compared with 5%), whereas a high proportion (i.e., overall 37%) of both age groups had deficient riboflavin status (EGRac ≥1.40). In multiple regression analysis, EGRac (P = 0.019) was a significant determinant of plasma PLP, along with dietary vitamin B-6 intake (P = 0.003), age (P < 0.001), BMI (kg/m2) (P = 0.031), and methylenetetrahydrofolate reductase gene (MTHFR) genotype (P < 0.001). Significant determinants of EGRac were dietary riboflavin intake (P < 0.001), age (P < 0.001) and MTHFR genotype (P = 0.020). Plasma PLP showed a stepwise decrease across riboflavin status categories from optimal (EGRac ≤1.26) to low (EGRac 1.27-1.39) to deficient status (P = 0.001), independent of dietary vitamin B-6 intake.

CONCLUSIONS

The findings are consistent with the known metabolic dependency of vitamin B-6 on riboflavin status and indicate that riboflavin may be the limiting nutrient, particularly in older people, for maintaining adequate vitamin B-6 status.

Identifying Key Predictors of Cognitive Dysfunction in Older People Using Supervised Machine Learning Techniques: Observational Study

BACKGROUND

Machine learning techniques, specifically classification algorithms, may be effective to help understand key health, nutritional, and environmental factors associated with cognitive function in aging populations.

OBJECTIVE

This study aims to use classification techniques to identify the key patient predictors that are considered most important in the classification of poorer cognitive performance, which is an early risk factor for dementia.

METHODS

Data were used from the Trinity-Ulster and Department of Agriculture study, which included detailed information on sociodemographic, clinical, biochemical, nutritional, and lifestyle factors in 5186 older adults recruited from the Republic of Ireland and Northern Ireland, a proportion of whom (987/5186, 19.03%) were followed up 5-7 years later for reassessment. Cognitive function at both time points was assessed using a battery of tests, including the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS), with a score <70 classed as poorer cognitive performance. This study trained 3 classifiers-decision trees, Naïve Bayes, and random forests-to classify the RBANS score and to identify key health, nutritional, and environmental predictors of cognitive performance and cognitive decline over the follow-up period. It assessed their performance, taking note of the variables that were deemed important for the optimized classifiers for their computational diagnostics.

RESULTS

In the classification of a low RBANS score (<70), our models performed well (F₁ score range 0.73-0.93), all highlighting the individual's score from the Timed Up and Go (TUG) test, the age at which the participant stopped education, and whether or not the participant's family reported memory concerns to be of key importance. The classification models performed well in classifying a greater rate of decline in the RBANS score (F₁ score range 0.66-0.85), also indicating the TUG score to be of key importance, followed by blood indicators: plasma homocysteine, vitamin B6 biomarker (plasma pyridoxal-5-phosphate), and glycated hemoglobin.

CONCLUSIONS

The results suggest that it may be possible for a health care professional to make an initial evaluation, with a high level of confidence, of the potential for cognitive dysfunction using only a few short, noninvasive questions, thus providing a quick, efficient, and noninvasive way to help them decide whether or not a patient requires a full cognitive evaluation. This approach has the potential benefits of making time and cost savings for health service providers and avoiding stress created through unnecessary cognitive assessments in low-risk patients.

Nutritional Epigenomics and Age-Related Disease

Recent advances in epigenetic research have enabled the development of epigenetic clocks, which have greatly enhanced our ability to investigate molecular processes that contribute to aging and age-related disease. These biomarkers offer the potential to measure the effect of environmental exposures linked to dynamic changes in DNA methylation, including nutrients, as factors in age-related disease. They also offer a compelling insight into how imbalances in the supply of nutrients, particularly B-vitamins, or polymorphisms in regulatory enzymes involved in 1-carbon metabolism, the key pathway that supplies methyl groups for epigenetic reactions, may influence epigenetic age and interindividual disease susceptibility. Evidence from recent studies is critically reviewed, focusing on the significant contribution of the epigenetic clock to nutritional epigenomics and its impact on health outcomes and age-related disease. Further longitudinal studies and randomized nutritional interventions are required to advance the field.

Riboflavin supplementation alters global and gene-specific DNA methylation in adults with the MTHFR 677 TT genotype

DNA methylation is important in regulating gene expression and genomic stability while aberrant DNA methylation is associated with disease. Riboflavin (FAD) is a cofactor for methylenetetrahydrofolate reductase (MTHFR), a critical enzyme in folate recycling, which generates methyl groups for homocysteine remethylation to methionine, the pre-cursor to the universal methyl donor S-adenosylmethionine (SAM). A polymorphism (C677T) in MTHFR results in decreased MTHFR activity and increased homocysteine concentration. Previous studies demonstrated that riboflavin modulates this phenotype in homozygous adults (MTHFR 677 TT genotype), however, DNA methylation was not considered. This study examined DNA methylation, globally and at key MTHFR regulatory sites, in adults stratified by MTHFR genotype and the effect of riboflavin supplementation on DNA methylation in individuals with the 677 TT genotype. Samples were accessed from participants, screened for the MTHFR C677T polymorphism, who participated in observational (n = 80) and targeted riboflavin (1.6 mg/day) RCTs (n = 80). DNA methylation at LINE-1 and key regulatory regions of the MTHFR locus were analysed by pyrosequencing in peripheral blood leukocytes. LINE-1 (+1.6%; p = 0.011) and MTHFR south shelf (+4.7%, p < 0.001) were significantly hypermethylated in individuals with the MTHFR 677 TT compared to CC genotype. Riboflavin supplementation resulted in decreased global methylation, albeit only significant at one CpG. A significant reduction in DNA methylation at the MTHFR north shore (-1.2%, p < 0.001) was also observed in TT adults following intervention with riboflavin. This provides the first RCT evidence that DNA methylation may be modulated by riboflavin in adults with the MTHFR 677 TT genotype.

Influence of nutrients involved in one-carbon metabolism on DNA methylation in adults—a systematic review and meta-analysis

Context

Aberrant DNA methylation is linked to various diseases. The supply of methyl groups for methylation reactions is mediated by S-adenosylmethionine, which depends on the availability of folate and related B vitamins.

Objectives

To investigate the influence of key nutrients involved in 1-carbon metabolism on DNA methylation in adults.

Data sources

Systematic literature searches were conducted in the Cochrane Library, Medline, Embase, Cumulative Index to Nursing and Allied Health Literature Plus, Scopus, and Web of Science databases. Studies that met the inclusion criteria and were published in English were included.

Data extraction

The first author, study design, sample size, population characteristics, type and duration of intervention, tissue type or cells analyzed, molecular techniques, and DNA methylation outcomes.

Data synthesis

A meta-analysis of randomized, controlled trials (RCTs) was conducted to investigate the effect of 1-carbon metabolism nutrients on global DNA methylation. Functional analysis and visualization were performed using BioVenn software.

Results

From a total of 2620 papers screened by title, 53 studies met the inclusion criteria. Qualitative analysis indicated significant associations between 1-carbon metabolism nutrients and DNA methylation. In meta-analysis of RCTs stratified by method of laboratory analysis, supplementation with folic acid alone or in combination with vitamin B12 significantly increased global DNA methylation in studies using liquid chromatography–mass spectrometry, which had markedly lower heterogeneity (n = 3; Z = 3.31; P = 0.0009; I2 = 0%) in comparison to other methods. Functional analysis highlighted a subset of 12 differentially methylated regions that were significantly related to folate and vitamin B12 biomarkers.

Conclusion

This study supports significant associations between 1-carbon metabolism nutrients and DNA methylation. However, standardization of DNA methylation techniques is recommended to reduce heterogeneity and facilitate comparison across studies.

Systematic Review registration

PROSPERO registration number: CRD42018091898.

Evidence of a Role for One-Carbon Metabolism in Blood Pressure: Can B Vitamin Intervention Address the Genetic Risk of Hypertension Owing to a Common Folate Polymorphism?

Hypertension in adulthood is recognized as the leading risk factor contributing to mortality worldwide, primarily from cardiovascular disease, whereas hypertension in pregnancy leads to serious adverse fetal and maternal outcomes. This article explores the under-recognized role of one-carbon metabolism in blood pressure (BP) and the potential for folate-related B vitamins to protect against hypertension. Genome-wide association studies and clinical studies provide evidence linking the 677C→T polymorphism in the gene encoding methylenetetrahydrofolate reductase (MTHFR) with BP and increased risk of hypertension and hypertension in pregnancy. A novel role for riboflavin (the MTHFR cofactor) has recently emerged, however, with evidence from randomized trials that supplemental riboflavin can lower BP specifically in adults with the variant MTHFR 677TT genotype. Further studies are required to elucidate the biological mechanisms linking one-carbon metabolism with BP and explore the effect of riboflavin in modulating the genetic risk of hypertension in early and later life.

Hyperglycemia and Metformin Use Are Associated With B Vitamin Deficiency and Cognitive Dysfunction in Older Adults

CONTEXT

Emerging evidence suggests that deficiencies of folate-related B vitamins can arise with metformin treatment and are independently linked with cognitive dysfunction, a comorbidity of diabetes.

OBJECTIVE

To determine the impact of hyperglycemia and metformin use on relevant B vitamin biomarkers and cognitive outcomes in older adults.

SETTING AND PARTICIPANTS

Community-dwelling older adults (74.1 ± 8.3 years, n = 4160) without dementia, recruited to the Trinity, Ulster and Department of Agriculture cohort study in 2008 to 2012, were classified as normoglycemic (n = 1856) or hyperglycemic, based on HbA1c ≥5.7% (39 mmol/mol), either with (n = 318) or without (n = 1986) metformin treatment.

MAIN OUTCOME MEASURES

Biomarkers of folate, vitamin B12, vitamin B6, and riboflavin were measured. Cognitive assessments included the Repeatable Battery for Assessment of Neuropsychological Status (RBANS) and the Frontal Assessment Battery (FAB).

RESULTS

Metformin use was associated with higher risk of deficiency of vitamin B12 (combined B12 index ≤-1; OR 1.45; 95% CI, 1.03 to 2.02) and vitamin B6 (plasma pyridoxal 5-phosphate <30.0 nmol/L; OR 1.48; 95% CI, 1.02 to 2.15). Fortified foods when eaten regularly had a positive impact on all relevant B vitamin biomarkers, even with hyperglycemia. After adjustment for relevant covariates, metformin use was associated with an increased risk of cognitive dysfunction as assessed with the RBANS (OR 1.36; 95% CI, 1.03 to 1.80) and FAB (OR 1.34; 95% CI, 1.03 to 1.74).

CONCLUSIONS

Use of metformin by older adults is associated with poorer cognitive performance; B vitamin deficiency may be implicated. Fortified foods can optimize B vitamin status and may be beneficial for maintaining better cognitive health in older people with or at risk for diabetes.

Greater yogurt consumption is associated with increased bone mineral density and physical function in older adults

In this cohort of community dwelling older adults (>60 years), we observed significant positive associations between the frequencies of yogurt intake with measures of bone density, bone biomarkers, and indicators of physical function. Improving yogurt intakes could be a valuable health strategy for maintaining bone health in older adults.

INTRODUCTION

The associations of yogurt intakes with bone health and frailty in older adults are not well documented. The aim was to investigate the association of yogurt intakes with bone mineral density (BMD), bone biomarkers, and physical function in 4310 Irish adults from the Trinity, Ulster, Department of Agriculture aging cohort study (TUDA).

METHODS

Bone measures included total hip, femoral neck, and vertebral BMD with bone biochemical markers. Physical function measures included Timed Up and Go (TUG), Instrumental Activities of Daily Living Scale, and Physical Self-Maintenance Scale.

RESULTS

Total hip and femoral neck BMD in females were 3.1-3.9% higher among those with the highest yogurt intakes (n = 970) compared to the lowest (n = 1109; P < 0.05) as were the TUG scores (-6.7%; P = 0.013). In males, tartrate-resistant acid phosphatase (TRAP 5b) concentrations were significantly lower in those with the highest yogurt intakes (-9.5%; P < 0.0001). In females, yogurt intake was a significant positive predictor of BMD at all regions. Each unit increase in yogurt intake in females was associated with a 31% lower risk of osteopenia (OR 0.69; 95% CI 0.49-0.96; P = 0.032) and a 39% lower risk of osteoporosis (OR 0.61; 95% CI 0.42-0.89; P = 0.012) and in males, a 52% lower risk of osteoporosis (OR 0.48; 95% CI 0.24-0.96; P = 0.038).

CONCLUSION

In this cohort, higher yogurt intake was associated with increased BMD and physical function scores. These results suggest that improving yogurt intakes could be a valuable public health strategy for maintaining bone health in older adults.

Dairy Intakes in Older Irish Adults and Effects on Vitamin Micronutrient Status: Data from the TUDA Study

BACKGROUND

Consumption of dairy products has been associated with positive health outcomes including a lower risk of hypertension, improved bone health and a reduction in the risk of type 2 diabetes. The suggested dairy intake for health in older adults is three servings per day but recent analysis of the NHANES data for older adults reported 98% were not meeting these recommendations. No studies have investigated the consequences of such declines in the dairy intakes of Irish older adults and the subsequent effects on vitamin micronutrient status.

OBJECTIVES

To study the daily dairy intakes of older Irish adults and to examine how the frequency of dairy food consumption affects vitamin micronutrient status.

METHODS

Participants (n 4,317) were from the Trinity Ulster Department of Agriculture (TUDA) Study, a large study of older Irish adults (aged >60 yrs) designed to investigate gene-nutrient interactions in the development of chronic diseases of aging. The daily intake portion for milk, cheese and yoghurt was calculated from food frequency questionnaire (FFQ) responses. Blood samples were analysed for vitamin biomarkers as follows: vitamin B12 (total serum cobalamin and holotranscobalamin (holoTC)), folate (red cell folate (RCF) and serum folate), vitamin B2 (erythrocyte glutathione reductase activation coefficient (EGRac)), vitamin B6 (serum pyridoxal phosphate) and vitamin D (serum 25(OH)D).

RESULTS

The mean total reported dairy intake was 1.16 (SD 0.79) portions per day with males consuming significantly fewer total dairy portions compared to females (1.07 vs 1.21 respectively) (P<0.05). There was no significant difference in total daily dairy serving intakes by age decade (60-69, 70-79, >80 yrs). Overall, only 3.5% of the total population (n 151) achieved the recommended daily dairy intake of three or more servings per day. A significantly higher proportion of females (4%) compared to males (2.4%) met these dairy requirements (P=0.011). Blood concentrations of vitamin B12 biomarkers, RCF, vitamin B2 and vitamin B6 were significantly worse in those with the lowest tertile of dairy intake (0-0.71 servings) compared to those in the highest tertile (1.50-4.50 servings) (P<0.05).

CONCLUSION

This study found that more than 96% of the older adults sampled did not meet current daily dairy intake recommendations. The study is the largest to-date examining dairy intakes in older Irish adults, and provides evidence that daily dairy intakes (in particular yogurt) contribute significantly to the B-vitamin and vitamin D biomarker status of older adults. These results suggest that older adults who are already vulnerable to micronutrient inadequacies, are forgoing the nutritional advantages of vitamin-rich dairy products.

Causes, Consequences and Public Health Implications of Low B-Vitamin Status in Ageing

The potential protective roles of folate and the metabolically related B-vitamins (vitamins B12, B6 and riboflavin) in diseases of ageing are of increasing research interest. The most common cause of folate and riboflavin deficiencies in older people is low dietary intake, whereas low B12 status is primarily associated with food-bound malabsorption, while sub-optimal vitamin B6 status is attributed to increased requirements in ageing. Observational evidence links low status of folate and the related B-vitamins (and/or elevated concentrations of homocysteine) with a higher risk of degenerative diseases including cardiovascular disease (CVD), cognitive dysfunction and osteoporosis. Deficient or low status of these B-vitamins alone or in combination with genetic polymorphisms, including the common MTHFR 677 C → T polymorphism, could contribute to greater disease risk in ageing by causing perturbations in one carbon metabolism. Moreover, interventions with the relevant B-vitamins to optimise status may have beneficial effects in preventing degenerative diseases. The precise mechanisms are unknown but many have been proposed involving the role of folate and the related B-vitamins as co-factors for one-carbon transfer reactions, which are fundamental for DNA and RNA biosynthesis and the maintenance of methylation reactions. This review will examine the evidence linking folate and related B-vitamins with health and disease in ageing, associated mechanisms and public health implications.

Novel Approaches to Investigate One-Carbon Metabolism and Related B-Vitamins in Blood Pressure

Hypertension, a major risk factor for heart disease and stroke, is the world's leading cause of preventable, premature death. A common polymorphism (677C→T) in the gene encoding the folate metabolizing enzyme methylenetetrahydrofolate reductase (MTHFR) is associated with increased blood pressure, and there is accumulating evidence demonstrating that this phenotype can be modulated, specifically in individuals with the MTHFR 677TT genotype, by the B-vitamin riboflavin, an essential co-factor for MTHFR. The underlying mechanism that links this polymorphism, and the related gene-nutrient interaction, with hypertension is currently unknown. Previous research has shown that 5-methyltetrahydrofolate, the product of the reaction catalysed by MTHFR, appears to be a positive allosteric modulator of endothelial nitric oxide synthase (eNOS) and may thus increase the production of nitric oxide, a potent vasodilator. Blood pressure follows a circadian pattern, peaking shortly after wakening and falling during the night, a phenomenon known as 'dipping'. Any deviation from this pattern, which can only be identified using ambulatory blood pressure monitoring (ABPM), has been associated with increased cardiovascular disease (CVD) risk. This review will consider the evidence linking this polymorphism and novel gene-nutrient interaction with hypertension and the potential mechanisms that might be involved. The role of ABPM in B-vitamin research and in nutrition research generally will also be reviewed.

EURRECA-Estimating folate requirements for deriving dietary reference values

In most countries, the dietary folate intake associated with adequate status of red cell folate and/or serum folate provides the basis for formulating reference values. One of the major challenges in setting dietary reference values for folate, however, is the need to account for the differences in bioavailability between the natural forms of the vitamin and the synthetic form, folic acid, albeit to date, few countries in Europe take bioavailability into consideration. A series of systematic reviews that included only those studies which used the most robust measures of both folate intake and folate status were carried out by the EURRECA Network of Excellence to examine the relationships between folate intake, status, and a number of health outcomes relevant to specific stages of the lifecycle. This review summarizes the available evidence and the issues to consider in the setting of dietary reference values for folate.

Biomarker responses to folic acid intervention in healthy adults: a meta-analysis of randomized controlled trials

BACKGROUND

The task of revising dietary folate recommendations for optimal health is complicated by a lack of data quantifying the biomarker response that reliably reflects a given folate intake.

OBJECTIVE

We conducted a dose-response meta-analysis in healthy adults to quantify the typical response of recognized folate biomarkers to a change in folic acid intake.

DESIGN

Electronic and bibliographic searches identified 19 randomized controlled trials that supplemented with folic acid and measured folate biomarkers before and after the intervention in apparently healthy adults aged ≥18 y. For each biomarker response, the regression coefficient (β) for individual studies and the overall pooled β were calculated by using random-effects meta-analysis.

RESULTS

Folate biomarkers (serum/plasma and red blood cell folate) increased in response to folic acid in a dose-response manner only up to an intake of 400 μg/d. Calculation of the overall pooled β for studies in the range of 50 to 400 μg/d indicated that a doubling of folic acid intake resulted in an increase in serum/plasma folate by 63% (71% for microbiological assay; 61% for nonmicrobiological assay) and red blood cell folate by 31% (irrespective of whether microbiological or other assay was used). Studies that used the microbiological assay indicated lower heterogeneity compared with studies using nonmicrobiological assays for determining serum/plasma (I(2) = 13.5% compared with I(2) = 77.2%) and red blood cell (I(2) = 45.9% compared with I(2) = 70.2%) folate.

CONCLUSIONS

Studies administering >400 μg folic acid/d show no dose-response relation and thus will not yield meaningful results for consideration when generating dietary folate recommendations. The calculated folate biomarker response to a given folic acid intake may be more robust with the use of a microbiological assay rather than alternative methods for blood folate measurement.

Vitamin B12 and ageing: current issues and interaction with folate

A compromised vitamin B12 status is common in older people despite dietary intakes that typically far exceed current recommendations. The maintenance of an optimal status of vitamin B12 is not only dependent on adequate dietary intake but more critically on effective absorption which diminishes with age. The measurement of vitamin B12 is complicated by the lack of a gold standard assay. There are a number of direct and functional indicators of vitamin B12 status; however, none of these are without limitations and should be used in combination. Vitamin B12 is of public health importance, not only because deficiency leads to megaloblastic anaemia and irreversible nerve damage, but also because emerging evidence links low B12 to an increased risk of a number of age-related diseases, including cardiovascular disease, cognitive dysfunction, dementia and osteoporosis. Furthermore, there are concerns relating to potential adverse effects for older adults with low vitamin B12 status of over-exposure to folic acid in countries where there is mandatory fortification of food with folic acid. The aim of this review is to examine the known and emerging issues related to vitamin B12 in ageing, its assessment and inter-relationship with folate.

Coronary artery bypass grafting (CABG) after initially successful percutaneous transluminal coronary angioplasty (PTCA): a review of 17 years experience

OBJECTIVE

Patients who undergo successful percutaneous transluminal coronary angioplasty (PTCA) may subsequently require operative myocardial revascularization. This review examines whether prior successful PTCA alters outcomes following subsequent coronary artery bypass grafting (CABG). The costs of interventional cardiology procedures and definitive surgery were also examined.

METHODS

From January 1981 through December 1997, 361 patients underwent CABG following initially successful PTCA (interval group). This group was compared with 11,909 patients who underwent CABG as the primary intervention for coronary artery disease (control group).

RESULTS

The average time interval to CABG following initial PTCA was 13.7 months. The post-CABG myocardial infarction rate was 4% for patients in the interval group and 3% for patients in the control group. The 30-day mortality was similar for both patient groups (2%). For the interval group, the average cost of total interventional management was 24,220 dollars per patient. This included average costs of 13,873 dollars for CABG and 10,347 dollars for all preoperative interventional cardiology procedures.

CONCLUSION

There is little doubt that PTCA procedures may provide successful myocardial revascularization. However, these procedures often need to be repeated over time and may serve only to delay coronary surgery, at substantial financial and personal cost.

Massive pulmonary embolus complicating left atrial myxoma

Atrial myxomas may present with a classic triad of constitutional symptoms, embolic events, and intracardiac obstruction (1). We report a case of a massive pulmonary thromboembolus complicating a left atrial myxoma in the absence of an atrial or ventricular septal defect.

Composite graft replacement of the aortic root after previous cardiac surgery: a 20-year experience

BACKGROUND

An aging population and prolonged survival of patients after cardiac operations has meant that composite aortic root replacement after previous cardiac operation is being performed with increasing frequency.

METHODS

From January 1979 to July 1999, 32 patients underwent "reoperative" composite replacement of the aortic root at our institution. Previous operations were 16 aortic valve replacement, 9 coronary artery bypass grafting, 5 repair aortic dissection, and 7 others. Indications for operation included ascending aortic aneurysm in 16 patients, ascending aortic dissections in 10 patients, and other in 6 patients.

RESULTS

The unit elective mortality was 3 of 26 (11.5%). One surgeon's elective mortality was 1 of 22 (4.6%). The unit emergent mortality was 6 of 6 (100%). There has been one late death. Morbidity was low.

CONCLUSIONS

Reoperative aortic root replacement is a technically demanding procedure, but expertise in the area achieves low elective mortality. Consideration should be given to aortic root replacement at the initial procedure. Close follow-up of postcardiac operation patients is necessary to proceed with elective aortic root replacement if indicated. Emergent presentation in the reoperative setting has a very poor prognosis.

Intermittent hypoxaemia without orthodeoxia due to right-to-left shunting related to an elongated aorta

An elderly woman presented with unexplained, intermittent hypoxaemia unrelated to posture. Subsequent investigations revealed intermittent and variable right-to-left interatrial shunting through a patent foramen ovale in the presence of normal pulmonary arterial and intracardiac pressures, caused by right atrial compression from a horizontal, elongated ascending aorta. Surgical closure of the foramen resulted in marked clinical improvement.

Lethal postoperative coronary artery spasm

BACKGROUND

Coronary artery spasm in the immediate postoperative period after a coronary operation is recognized infrequently. Its severity is variable and manifestations unpredictable. The diagnosis is usually made by an awareness of the possibility and thereafter by exclusion of other causes of myocardial ischemia. An opportunity for a positive diagnosis is rarely available.

METHODS

The case reports of 3 patients with similar presentations of ischemic heart disease and with severe manifestations of coronary artery spasm in the postoperative period are presented.

RESULTS

All 3 patients were women aged 55 to 60 years. All had single-vessel coronary artery disease involving the left anterior descending artery and underwent a left internal mammary artery bypass graft. Severe manifestations of myocardial ischemia of abrupt onset developed approximately 7 hours postoperatively in each patient. One patient died of severe hemodynamic deterioration from which resuscitation was unsuccessful. Another sustained a large anterior myocardial infarction despite graft patency. The third patient was supported by an intraaortic balloon pump and made a full recovery.

CONCLUSIONS

The early diagnosis of coronary artery spasm is achieved by an awareness of the condition. The institution of early appropriate management may prevent its consequences.

Left ventricular false aneurysm after previous repair of acquired ventricular septal defect

We report a novel case of a 69-year-old woman who was treated surgically for a postinfarction inferior ventricular septal defect and presented 3 years postoperatively with a large left ventricular false aneurysm. This was successfully repaired.

The body's response to processing emotional trauma: linking verbal text with autonomic activity

When individuals talk or think about upsetting experiences, different coping and defensive processes are invoked from one minute to the next. Further, some coping strategies are thought to be more effortful and to be associated with greater biological activity than others. The present research sought to identify how the expression of emotions and the use of different psychological defenses were reflected in momentary changes in autonomic nervous system activity while subjects wrote about emotional topics. A new methodology is introduced that links the production of natural written language with autonomic activity on a word-by-word or phrase-by-phrase basis. Using this technique with a sample of 24 subjects who wrote about traumatic experiences, it was found that certain text dimensions are highly related to skin conductance level (SCL) but not heart rate. In general, subjects' SCLs increased when expressing negative emotions and when using denial and the passive voice. SCLs were more likely to drop when subjects used positive emotion words and self-references and at the conclusion of sentences or thought units. Implications for this methodology for understanding psychological defense and physical health are discussed.

Video-assisted thoracoscopy

Recent advances in video-imaging and minimally invasive surgical instrumentation have expanded the role of thoracoscopy in the diagnosis and treatment of intrathoracic conditions. This prospective study describes the use of video-assisted thoracoscopy (VAT) in 100 consecutive patients. There were 70 males and 30 females with a mean age of 54.6. They underwent 103 VAT procedures with 41 thoracoscopic biopsies of lung, pleural, chest wall and mediastinal abnormalities, 32 for treatment of recurrent or persistent pneumothorax, 18 for thoracoscopic assessment of pulmonary and pleural tumours and 12 for thoracoscopic resection of peripheral lung lesions, chest wall, mediastinal and pleural tumours. Eighty-one patients had VAT procedures alone while the remaining 19 had VAT proceeding to thoracotomy. The mean operating time for VAT alone was 51 min (range 30-135 min). There were no operative deaths. There were 8 significant complications from which patients recovered fully. Patients who underwent VAT alone were shown to have earlier postoperative mobilization, reduction in parenteral analgesic requirement and reduced length of hospital stay compared to patients undergoing additional thoracotomy. A telephone survey of patients on returning home showed that patients undergoing VAT alone returned to full activity earlier than those who had thoracotomy (mean 9.0 vs mean 19.4 days). This study confirms that VAT is a safe and effective procedure in the management of pulmonary, mediastinal and pleural disease and the treatment of persistent and recurrent pneumothorax. Its role in the resection of pulmonary malignancy remains to be defined.

Relation between age, arterial distensibility, and aortic dilatation in the Marfan syndrome

This study examined the relations between age, arterial distensibility, and systemic hemodynamics in patients with the Marfan syndrome. The study group included 170 patients referred to a specialist clinic, of whom 55 (age 26 +/- 12 years) were diagnosed as having Marfan syndrome. The remaining 115 patients (age 25 +/- 14 years) formed a control group. Each patient underwent echocardiographic examination, with measurement of ascending aorta diameter at end-diastole and end-systole, and aortic flow velocities. The elastic properties of the aorta were indexed by calculation of aortic distensibility, wall stiffness, and systemic pulse wave velocity. Mean end-diastolic aortic diameter in the Marfan group (38 +/- 9 mm) was greater than that in the controls (26 +/- 4 mm, p < 0.01). Resting heart rate and aortic flow velocities were similar in the 2 groups, but systemic arterial pulse pressure was greater in the Marfan group (50 +/- 12 mm Hg) than in the controls (41 +/- 8 mm Hg, p < 0.01). Aortic diameter increased with age in both groups, but at all ages the Marfan group exhibited greater aortic diameters (p < 0.05). Aortic distensibility was less in the Marfan group (2.6 +/- 1.3 cm2.dynes-1 x10(-6)) than in the controls (6.2 +/- 2.1 cm2.dynes-1 x 10(-6), p < 0.01), and the aortic wall stiffness index was greater in the Marfan group (7.9 +/- 3.4) than in the controls (2.8 +/- 0.6, p < 0.01). Aortic wall stiffness increased with age and aortic diameter, but at all ages the Marfan group exhibited a stiffer aorta for a given diameter than did the controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Post-traumatic chronic false aneurysm of the ascending aorta with long-term survival

The case of a patient with impending rupture of a post-traumatic chronic false aneurysm of the ascending aorta is presented. It is stressed that chronic false aneurysms of the ascending aorta are rare and that a chronic false aneurysm of any part of the aorta carries a high risk of delayed rupture at any time.

Optic nerve sheath decompression for visual loss in patients with acquired immunodeficiency syndrome and cryptococcal meningitis with papilledema

Visual dysfunction developing in association with acquired immunodeficiency syndrome (AIDS) can be multifactorial. Two patients with this syndrome and cryptococcal meningitis had papilledema and visual loss. Both were treated by optic nerve sheath fenestration. One patient had bilateral nonsimultaneous optic nerve sheath fenestrations; visual function improved in one eye. The other patient had bilateral visual improvement after a unilateral optic nerve sheath fenestration. Cryptococcal organisms were present in the dural sheath specimens of both patients despite ongoing therapy with antifungal medication. Postoperative orbital infectious complications did not occur. Autopsy examination of one patient showed that the sites of fenestration were patent. Medical treatment of cryptococcal meningitis associated with AIDS has a guarded prognosis. Optic nerve sheath fenestration offers a treatment alternative for papilledema and visual loss that occur with cryptococcal meningitis.

The natural history of aortic dilatation in Marfan syndrome

OBJECTIVES

To determine the relationship between age and aortic dilatation in patients with Marfan syndrome and to define the rate of progression of aortic dilatation in these patients.

DESIGN

All patients were evaluated in a multidisciplinary clinic to establish a firm diagnosis of Marfan syndrome. Aortic dimensions were measured by echocardiography and patients with Marfan syndrome were followed up with annual physical and echocardiographic examinations to detect any change in aortic diameter over the subsequent four years.

PATIENTS

One hundred and fifty-seven patients were referred to the clinic for assessment, of whom 40 exhibited diagnostic features of Marfan syndrome. Only 24 of these patients had previously been diagnosed with Marfan syndrome, while 17 other patients, previously diagnosed with Marfan syndrome, had insufficient clinical features to justify the diagnosis.

RESULTS

Among the 40 patients (19 male, 21 female) with Marfan syndrome (mean age, 28 +/- 15 years), the prevalence of cardiovascular abnormalities was 90%. Aortic root dilatation was present in 78% of patients, aortic regurgitation in 28%, mitral valve prolapse in 65% and mitral regurgitation in 35%. Mean aortic root diameter in the Marfan patients (21.4 +/- 4.0 mm/m2 body surface area) markedly exceeded that of age and sex matched controls without Marfan syndrome (14.9 +/- 2.2 mm/m2) and that of first-degree relatives without Marfan syndrome (15.3 +/- 2.9 mm/m2). The occurrence of aortic dilatation in Marfan syndrome was variable, with patients as young as 20 years exhibiting severe dilatation. All patients with Marfan syndrome exhibiting aortic dilatation were advised to take beta-adrenergic blocking drugs, unless contraindicated, in an effort to retard the rate of aortic dilatation. Among 33 patients followed up for at least one year, 14 (42%) exhibited an increase in aortic diameter of at least 2 mm, while 16 of 23 patients (70%) followed up for at least three years exhibited similar progression of aortic dilatation. The overall mean rate of dilatation in the Marfan patients was 1.9 mm per year. Nine patients developed aortic dilatation of more than 50 mm diameter during four years' follow-up and required surgical repair of the aorta. Each of these patients is well at between three months' and four years' follow-up.

CONCLUSIONS

Aneurysmal dilatation of the aorta is a common complication of Marfan syndrome and may become manifest at an early age. Furthermore, aortic dilatation can progress rapidly, even in the absence of symptoms. Individuals with Marfan syndrome should have annual echocardiographic examinations to monitor aortic root dimensions, and those exhibiting rapid progression of aortic dilatation or an aortic root diameter in excess of 50 mm, should be considered for elective composite graft repair of the aorta.

Predominant alpha 1-adrenoceptor-mediated contraction in the human internal mammary artery

alpha-Adrenoceptor agonists and antagonists are widely used perioperatively for internal mammary artery (IMA)-coronary artery bypass operations. To determine subtypes of alpha-adrenoceptors in the human IMA, we studied responses of isolated human IMA segments to alpha-adrenoceptor agonists, antagonists, and electrical stimulation in organ baths. The IMA ring segments (3 mm long) were set up at a physiologic and comparable condition according to their own length-tension curves. alpha 1-Agonist methoxamine (MO) induced 2.65 +/- 0.70 g force and alpha 1, alpha 2-agonist norepinephrine (NE) induced 4.07 +/- 0.70 g force. The contractions induced by both MO and NE were totally abolished by alpha 1-antagonist prazosin (0.1 microM) but not alpha 2-antagonist yohimbine. alpha 2-Agonist UK14304 induced only 0.39 +/- 0.17 g force, which was significantly less than that induced by MO or NE (p < 0.001). Contractions induced by electrical field stimulation (2, 10, 20 Hz) were decreased by alpha 1-antagonist prazosin 1 microM (p < 0.01) but potentiated by alpha 2-antagonist yohimbine. These results strongly suggest that in the human IMA the postjunctional alpha-adrenoceptors are predominantly of the alpha 1-subtype and therefore the alpha-adrenoceptor agonist-induced contraction and the sympathetic nerve stimulation-induced contraction is mediated mainly by activation of the alpha 1-adrenoceptors.

"Serpentine heart". Direct observation of the human heart during profound hyperkalemia

We observed cardiac contractility in a patient who had inadvertently received a massive overdose of potassium chloride during open heart surgery. Slowly advancing waves of contraction were present while the surface electrocardiogram showed the sine wave configuration typical of severe hyperkalemia. This is the first report of such an observation and may serve to promote proper diagnosis and treatment of similar cases.

Mitral stenosis in the Maroteaux-Lamy syndrome: a treatable cause of dyspnoea

The case is reported of a young woman with the Maroteaux-Lamy syndrome (mucopolysaccharidosis type VI) who presented with rapidly progressive dyspnoea due to mitral stenosis. Mitral valve replacement was performed and the appearance of the valve was typical of mucopolysaccharide infiltration. Dyspnoea in patients with the Maroteaux-Lamy syndrome may be due primarily to cardiac valve involvement, and in this setting, valve surgery is safe and effective.

Persistent ductus arteriosus in adults. A review of surgical experience with 25 patients

OBJECTIVE

To review the clinical features, operative details and course of adults with persistent ductus arteriosus.

DESIGN

Retrospective study. Information on subjects was obtained by case records review.

SETTING

The Cardiothoracic Unit, Royal Prince Alfred Hospital, Sydney.

PATIENTS

Twenty-five adults aged 16 years and over with persistent ductus arteriosus, from 1974-1990.

INTERVENTION

Surgical division or ligation of persistent ductus, via left thoracotomy or median sternotomy.

MAIN OUTCOME MEASURES

Preoperative clinical features; postoperative mortality and morbidity.

RESULTS

There was a high incidence of symptoms in this group of adults with persistent ductus arteriosus, many having anatomical (aneurysm, calcification) and/or haemodynamic (heart failure, pulmonary hypertension) complications. There was one death (mortality, 4%) of a young woman with significant preoperative pulmonary hypertension. The remaining 24 patients (96%) left hospital completely well between 4 and 12 days after surgery.

CONCLUSIONS

Persistent ductus arteriosus, although primarily a paediatric problem, may present in adulthood. Closure by operative means (or in selected cases, by interventional catheter) is warranted in all adult subjects with left to right shunt, other than for patients over 60 years of age with neither heart failure nor cardiomegaly.