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Bone Mineral Density and Fat-SolubleVitamin Status in Adults with CysticFibrosis Undergoing Lung Transplantation:A Pilot Study

GRACE HUBERT, RD BSca; THERESA TAM CHUNG, RD BSca; CONNIE PROSSER, PhD FCACBb; DALE LIEN, MDc;JUSTIN WEINKAUF, MDc; NEIL BROWN, MDc; MARIANNE GOODVIN, RN BNScd; KATHY JACKSON, RN BNScd;JOAN TABAK, RNe; JOSETTE SALGADO, RN BNSce; ABEER SALMAN ALZABEN, MScf; DIANA R. MAGER, PhD MSc RDfg"Nutrition Services, Alberta Health Services, Edmonton, AB; bDepartment of Laboratory Medicine, University of Alberta, Edmonton, AB; 'Division of PulmonaryMedicine, Department of Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB; dLung Transplant Program, Alberta Health Services,Edmonton, AB; "Adult Cystic Fibrosis Clinic, Alberta Health Services, Edmonton, AB; fDepartment of Agricultural, Food and Nutritional Science, University ofAlberta, Edmonton, AB; gDepartment of Pediatrics, University of Alberta, Edmonton, AB

ABSTRACTPurpose: Patients with cystic fibrosis (CF) often experience low bonemineral density (BMD) pre- and post-lung transplantation (LTX). Thestudy purpose was to describe BMD and micronutrient status in adultswith CF pre- and post-LTX.Methods: Twelve patients with CF (29 ± 8 years) were recruited fromthe CF clinic at the University of Alberta Lung Transplant Program.BMD and vitamins A, D, E, K status, and parathyroid hormone weremeasured pre- and post-LTX.Results: No significant differences pre- and post-LTX were observed atthe different bone sites measured (lumber-spine, femoral-neck (FN),hip, and femoral-trochlea) (p) 0.05). BMD T-scores «-2) was presentin lumbar-spine, FN, hip, and femoral-trochlea in 33%, 17%, 17%, and25% of individuals pre-LTX and 58%, 33%, 58%, and 33% of indivi­duals post-LTX, respectively. More than 50% of patients had subopti­mal vitamin K levels (PIVKA-li values) 3 ng/mL) pre- and post-LTX.Conclusion: Adults with CF pre- and post-LTX had reduced BMD andsuboptimal vitamin K status.(Can I Diet Pract Res. 2016;77:1-4)(DOl: 10.3148/cjdpr-2016-014)Published at dcjournal.ca on 19 July 2016.

INTRODUCTIONMaintenance of bone health in patients with cystic fibrosis(CF) is an ongoing challenge, especially as the disease becomesmore severe and the need for lung transplantation (LTX)becomes more eminent [1]. Pre-LTX and post-LTX, indivi­duals with CF are at high risk for low bone mineral density(BMD) related to chronic use of corticosteroid and otherimmunosuppressive therapy (such as tacrolimus), antibioticuse and chronic undernutrition secondary to poor intake,increased energy expenditure, and pancreatic insufficiency

RESUMEObjectif. Les patients atteints de fibrose kystique (FK)ont souvent unedensite minerale osseuse (DMO) faible avant et apres la transplanta­tion pulmonaire (TP). L'objectif de l'etude etait de decrire la DMO etl'etat nutritionnel en micronutriments des adultes atteints de FKavantet apres la TP.Methodes. Douze patients atteints de FK (29 ± 8 ans) ont ete recrutesIi la clinique de FK du programme de transplantation pulmonaire del'Universite de l'Alberta. La DMO et l'etat nutritionnel en vitamines A,D, E et K, et I'hormone parathyro'lde ont ete rnesures avant et apresla TP.Resultats. Aucune difference significative n'a ete observee avant etapres la TP aux differents sites osseux mesures (rachis lombaire, colfemoral, hanche et trochlea femorale) (p ) 0,05). Des scores T de laDMO « - 2) etaicnt presents dans Ie rachis lombaire, Ie col femoral,la hanche et la trochlea femorale chez 33 %, 17 %, 17 % et 25 %des personnes avant la TP et chez 58 %, 33 %, 58 % et 33 % des per­sonnes apres la TP, respectivement. Plus de 50% des patients avaientdes taux de vitamine K sous-optimaux (concentrations de PIVKA-II ) 3ng/rnl) avant et apres la TP.Conclusion. Les adultes atteints de FKavaient une DMO reduite et untaux de vitamine K sous-optimal avant et apres la TP.

(Rev can prat rech dletet. 2016;77: 1-4)(DOl: 10.3148/cjdpr-2016-014)Publie au dcjournal.ca Ie 19 juillet 2016.

[2-4). Suboptimal fat-soluble vitamin intake due to inadequateor poor diet quality and/or noncompliance to prescribed vita­min supplementation can also contribute to low BMD. Severalstudies have shown that fat-soluble vitamins can be low pre­LTX [5-7), whereas post-LTX, hypervitaminnosis A can con­tribute to low BMD [8).

The University of Alberta Lung Transplant Program pro­vides LTX for patients with end-stage lung disease fromAlberta, including individuals with CF who have a reported60%-75% 5-year survival rate [9). With increased survival,

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poor bone health is a significant concern, especially as it relatesto increased morbidity and mortality and overall quality oflife [4, 10]. Limited exposure to sunlight in northern climatesalso increases the risk for vitamin D (vitD) deficiency andsubsequent poor bone health. For these reasons, patientsare routinely supplemented with commercially available fat­soluble vitamins (A, D, E, and K) pre- and post-LTX.Although suboptimal vitamin K (vitK) status has been shownto be a contributor to low bone health in many clinical popu­lations [11], it is currently unknown what the current preva­lence of suboptimal vitK status is in adult patients post-LTX.This is particularly relevant in the CF population, as on-goingfat malabsorption due to pancreatic insufficiency is not cor­rected or improved by lung transplantation. This pilot studydescribes BMD and fat-soluble vitamin status in adult CF sub­jects, pre- and post -LTX.

METHODSEthics approval (Pro 00001737) was obtained from theHuman Research Ethics Board at the University of Albertaprior to study initiation. Adult CF patients (age> 18 years)who were referred to the University of Alberta Lung Trans­plant program between 2005 and 2012 were recruited andenrolled over a 12-month period. Study inclusion criteriaincluded those on anti-resorptive therapy, as this is part ofroutine clinical care. Exclusion criteria included terminal ill­ness, intensive care unit stay >72 hours, and subjects whowere unable to provide informed consent. A total of 25patients with CF undergoing lung transplant assessmentwere screened for eligibility; 13 were excluded due to coincid­ing illness requiring hospitalization, early lung TX, and/orrefusal to participate. No Significant differences in demo­graphic or anthropometric variables were noted between thosewho agreed to participate in the study and those who did not.Informed consent was obtained from all participants. Heightand weight were measured using validated techniques.

Blood was collected for measurement of vitamins A, D, E,and K (protein indicated in vitamin K absence (PIVKA-II))and parathyroid hormone (PTH) at LTX assessment and at3, 6, and 12 months post-LTX. The samples were analyzedaccording to standardized methodologies in the Core Labora­tory at Alberta Health Services [12]. Serum 25-hydroxy vita­min D (25(OH)D) concentrations were assessed according tothe Canadian Endocrine Practice Guidelines «75 nmol/L,insufficient/suboptimal; >75 nrnol/L, optimal) [13]. BMDwas measured using hologic dual-energy X-ray absorptiome­try 450 at LTX assessment and at 9 and 18 months post­LTX (whole body, hip, femoral-neck (FN), femoral-trochlea,lumbar-spine).

Analyses were performed using Statistical Analysis Soft­ware (SAS; version 9.4 SAS Institute, Cary, NC, USA). Datawere analyzed by treating individual patient data as singlemeasures, rather than repeated measures due to the small sam­ple size at each individual time point. Continuous variableswere expressed as mean ± SD. Normality was assessed using

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the Shapiro-Wilk test. Non-parametric variables were logtransformed. Continuous variables were analyzed usingdependent t test to assess differences pre- and post-LTX withadjustments for potential confounding variables (season, age,sex). Statistical Significance was determined at P < 0.05.

RESULTSDemographic, anthropometric, and laboratory dataAnthropometric and demographic data for the 12 patientspre- and post-LTX are shown in Table 1. No significant agedifference at time of LTX assessment was observed betweensexes (males, 29 ± 10 years vs. females, 31 ± 6 years; P = 0.70).A total of 42% (n = 5) and 17% (n = 2) of participantshad a mean BMI reflective of suboptimal nutritional status(BMI < 18.5) pre- and post-LTX, respectively. Laboratorydata are shown in Table 2. Although there was no Significantdifference in estimated glomerular filtration rate (GFR), valuesin 58% of patients were indicative of renal insufficiency (GFR<60; stage 3 chronic kidney disease) post-LTX. In addition,significant differences in urea, creatinine, and PTH pre- andpost-LTX were noted, indicating worsening renal functionand secondary hyperparathyroidism in 83% of patients post­LTX. The majority of patients (67% pre-LTX and 58% post­LTX) had optimal 25(OH) vitD levels (>75 nrnol/L), likelysecondary to vitD supplementation (400-8700 IV/d) [13]. Atotal of 58% and 55% of patients had suboptimal vitK status(PIVKA-II values >3 ng/mL) pre- and post-LTX, respectively,despite routine recommendation for vitK supplementation

Table 1. Anthropometric and bone health variables pre- andpost-LTX in adult patients with cystic fibrosis.

Pre-LTX Post-LTXAnthropometrics (n=12; 7M, 5W (n=12; 7M, 5F)a p

Age (y) 29 ± 8 (19-49) 30 ± 8 (19-52) 0.371Weight (kg)b 54.8 ± 9.0 60.3 ± 5.6 0.098

(39.1-71.0) (51.4-67.8)Height (m) 1.68 ± 0.08 1.68 ± 0.08 >0.05

(1.55-1.81) (1.55-1.81)BMI (kg/m2)b 19.3 ± 3.2 21.4 ± 2.4 0.103

(15.1- 25.7) (17.5-25.0)Spine BMD 0.86 ± 0.11 0.86 ± 0.10 0.992(gm/c2)C (0.69-1.03) (0.69-1.07)Hip BMD 0.82 ± 0.14 0.77 ± 0.12 0.262(gm/cm2)C (0.57-1.08) (0.54-1.04)Femoral-neck 0.71 ± 0.10 0.67 ± 0.11 0.324BMD (grn/crrr')" (0.56-0.90) (0.54-0.91)Femoral- 0.60 ± 0.11 0.55 ± 0.10 0.166trochlea BMD (0.43-0.82) (0.40-0.77)(grn/cm)"'Dataarepresentedasmean± standarddivision(range).bThenumberof measurementspost-LTXwas11.'Thenumberof repeatedmeasurementspost-LTXwas22.Note:LTX,lungtransplantation;M,male;F. female;BMI,bodymassindex;BMD.bonemineraldensity.

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Table 2. Laboratory variables pre- and post-LTXin adult patients with cystic fibrosis

Biochemical Pre-LTX(n=12)a Post-LTX(n=12)a Normal referenceranges pVitamin A (IJmoI/L)b 1.4 ± 0.3 (0.8-2.0) 2.7 ± 0.8 (1.3-4.0) 1.5-3.5 <0.001PIVKAII (ng/rnl)" 80.0 ± 171.9 (0.1-427.8) 6.4 ± 14.2 (0.1-64.2) ,,3 0.206Vitamin E (IJmoI/L)b 26 ± 9 (10-43) 40 ± 18 (13-86) 12-45 0.010Calcium (mrnol/l)'' 2.25 ± 0.10 (2.08-2.38) 2.26 ± 0.13 (2.10-2.80) 2.10-2.60 0.773PTH(prnol/l)" 4.4 ± 3.9 (1.4-160) 9.8 ± 11.9 (2.1-61.0) 1.2-6.8 0.02525(OH)D (nrnol/L)" 83 ± 40 (10-154) 85 ± 23 (43-141) <75 0.798Urea (mrnol/L)" 4.3 ± 1.5 (1.2-6.8) 7.1 ± 2.8 (19-10.7) 2.5-8.0 0.006Creatinine (IJmoI/L)f 64 ± 18 (35-99) 108 ± 35 (48-166) M: 50-115 F: 50-105 <0.001GFR(ml/min/1.73 m2)g 60 ± 0 (60-60) 53 ± 9 (30-60) >60 0.090HemoglobinA1C (%)h 6.34 ± 0.57 (5.5-7.4) 6.11 ± 0.47 (5.4-7.1) <6.1 >0.05'Data are presentedas mean ± standard division (range).bThenumberof measurementspre-L1Xwas 12; the number of repeatedmeasurementspost-L1Xwas 33'The numberof measurementspre-Llx was 11; the number of repeatedmeasurementspost-Llx was 20.dThenumberof measurementspre-L1Xwas 12; the number of repeatedmeasurementspost-L1Xwas 34.'The numberof measurementspre-Ux was 12; the number of repeatedmeasurementspost-L1Xwas 13.rThenumberof measurementspre-Ux was 12; the number of repeatedmeasurementsposH1X was 24.gThenumberof measurementspre-Llx was 6; the number of repeatedmeasurementsposHTXwas 17."None of the participantspre-L1Xwereon exogenous insulin vs 83% post-L1Xwho were on exogenousinsulin.Note: L1X,lung transplantation; PIVKAII, proteins Induced by vitamin KabsenceII; PTH,parathyroidhormone; 25(OH)D,25-hydroxy vitamin D;GFR, glomerular filtration rate.

(> 1 mg/d). Significant differences in serum retinol levels andvitamin E levels were also observed pre- and post- LTX (P <0.05) with daily vitamin A (26 501 ± 14040 IU/d) and vitaminE (260 ± 179 IU/d) supplementation. Routine vitamin supple­mentation was typically in the form of single vitD (>1000 IU)and/or multivitamin preparations.

Bone mineral densityBMD data are shown in Table 1 and Figure 1. No significantdifferences pre- and post-LTX were observed at the differentsite measures (lumbar-spine, FN, hip and femoral-trochlea)(P > 0.05). With the exception of spinal-BMD (absolute;

Figure 1. The average T-scoreof spine, hip, femoral-neckand femoral-trochlea pre- (n=12) and post-lung transplant

(LTX)in adult patients with cystic fibrosis (n=12). Thenumber of measurementspost-LTXwas n=22 for hip,

femoral-neck, and femoral-trochlea and n=23 for spine.

0.0

-0.5

-1.0Q)8 -1.5

.: -2.0IIPre-LTX

-+---1--1----1--1----1--1-- ..Post-LTX

-2.5+--I--I-----=.----I----~--3.0+-+-1:----------- _

-3.5L.---------·- _Spine Hip Femoral Neck Femoral

Trochlea

females, 0.91 ± 0.08 vs males, 0.82 ± 0.09 gm/cm/, P = 0.002)and T scores (females, -1.27 ± 0.79 vs males, -2.25 ± 1.26;P == 0.015), no Significant differences in absolute or T scoreswere observed between sexes at the different sites measured(P> 0.05). BMD T scores «-2) indicative of osteoporosiswere present in lumbar-spine, hip, FN, and femoral-trochleain 33%, 17%, 17%, and 25% individuals pre-LTX, respectively.In contrast, BMD T scores «-2) were present in lumbar­spine, hip, FN and femoral-trochlea in 58%, 33%, 58%, and33% individuals post-LTX, respectively.

DISCUSSIONThis is a descriptive, pilot study that describes fat-soluble vita­min status and BMD in adults with CF pre- and post-LTX in anorthern Canadian LTX program. A Significant finding is thatthe majority of patients had reduced BMD and suboptimalvitK status, despite healthcare practitioner recommendationfor fat-soluble vitamin supplementation. Several factors mayhave influenced these findings such as low patient adherenceto prescriber recommendation, ongoing pancreatic in­sufficiency and malabsorption refractive to pancreaticenzyme replacement therapy, poor diet quality, reduced weight­bearing activities, and use of immunosuppressive medicationssuch as corticosteroids, tacrolimus, and antibiotics (e.g., tobra­mycin) [14, 15]. Many patients in this cohort were under­weight at the time of LTX and hence had suboptimalnutritional status. Although, weight status improved post­LTX, deficits in nutritional intake and weight-bearing activity,ongoing pancreatic insufficiency and the use of corticosteroidtherapy (typically 10-15 mg/d, but tapered down to alternativeday therapy and/or discontinuation by 6-12 months), and/or

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other medications such as tacrolimus may have contributed toreduced BMD [9, 15-17].

Suboptimal vitD status is highly prevalent in northern cli­mates like Alberta [18, 19]. Although patients in general hadserum 25(OH)D levels above 75 nmol/L and normal PTHlevels, higher vitD levels in conjunction with weight-bearingactivities may be needed to optimize bone health pre- andpost-LTX. Findings regarding poor bone health are similarto other LTX centres where ongoing nutritional challenges inadult LTX recipients place them at high risk for poor bonehealth [20]. A major limitation in this study includes the smallsample size, which limits the overall generalizability of thefindings. However, a post-hoc power test indicated sufficientpower (~ > 0.8) to discriminate reduced BMD at the differentsites pre- and post-LTX.

Unique findings include the high prevalence of suboptimalvitK status post-LTX. These findings underscore the impor­tance of routine follow-up by healthcare practitioners inpatients with CF undergoing LTX. Future studies should focuson assessing adherence to vitamin therapy, and the impact ofvitK supplementation on bone health parameters.

RELEVANCE TO PRACTICEPatients with CF are at high risk for poor bone health andmicronutrient insufficiency, This underscores the need forhighly specialized medical teams to address ongoing micronu­trient deficiencies in this population. Registered Dietitians areuniquely positioned to help optimize bone health and micro­nutrient status by developing effective nutrition care plansand exploring the barriers and facilitators to achieving nutri­tional goals in complex care populations.

AcknowledgementsThe authors gratefully acknowledge the participants in thisstudy.

Funding: Canadian Lung Transplantation Study Group.Personal funding for ASA by the King Abdullah Programfor Scholarship- Saudi Cultural Bureau is also gratefullyacknowledged.

Conflicts of interest: None to report.

References1. Elkin SL, Fairney A, Burnett S, Kemp M, Kyd P, Burgess J, et at. Vertebral

deformities and low bone mineral density in adults with cystic fibrosis:a cross-sectional study. Osteoporos Int. 2001;12(5):366-72. doi: 10.10071s001980170104.

2. Bianchi ML, Romano G, Saraifoger S, Costantini D, Limonta C, ColomboC. BMD and body composition in children and young patients affectedby cystic fibrosis. J Bone Miner Res. 2006;21(3):388-96. doi: 10.13591JBMR.051106.

4 Revue canadienne de la pratique et de la recherche en dietetique - Vol 77, 2016

3. Aris RM, Merkel PA, Bachrach LK, Borowitz DS, Boyle MP, Elkin SL,et at. Guide to bone health and disease in cystic fibrosis. J Clin EndocrinolMetab. 2005;90(3):1888-96. doi: 10.1210/jc.2004-1629.

4. Fok J, Brown NE, Zuberbuhler P, Tabak J, Tom M. Low bone mineraldensity in cystic fibrosis patients. Can J Diet Pract Res. 2002;63(4):192-7. doi: 10.3148/63.4.2002.192.

5. Culhane S, George C, Pearo B, Spoede E. Malnutrition in cystic fibrosis: areview. Nutr Clin Pract. 2013;28(6):676-83. doi: 10.1177/0884533613507086.

6. Maqbool A, Stallings VA. Update on fat-soluble vitamins in cysticfibrosis. Curr Opin Pulm Med. 2008;14(6):574-81. doi: 10.1097/MCP.oto 13e3283136787.

7. Lowery EM, Bemiss B, Cascino T, Durazo-Arvizu RA, Forsythe SM, AlexC, et at. Low vitamin D levels are associated with increased rejection andinfections after lung transplantation. J Heart Lung Transplant. 2012;31(7):700-7. doi: 10.1016/j.healun.2012.02.012.

8. Ho T, Gupta S, Brotherwood M, Robert R, Cortes D, Verjee Z, et at.Increased serum vitamin A and E levels after lung transplantation.Transplantation. 2011;92(5):601-6. doi: 10.1097ITP.Ob013e31822790e3.

9. Fidalgo P, Ahmed M, Meyer SR, Lien D, Weinkauf J, Kapasi A, et al.Association between transient acute kidney injury and morbidity andmortality after lung transplantation: a retrospective cohort study. J CritCare. 2014;29(6):1028-34. doi: 10.1016/j.jcrc.2014.07.024.

10. Santana MJ, Feeny D, Jackson K, Weinkauf J, Lien D. Improvement inhealth-related quality of life after lung transplantation. Can Respir J.2009;16(5):153-8. doi: 10.1155/2009/843215.

11. Bertolaso C, Groleau V, Schall II, Maqbool A, Mascarenhas M, LathamNE, et at. Fat-soluble vitamins in cystic fibrosis and pancreatic insufficiency:efficacy of a nutrition intervention. IPediatr Gastroenterol Nutr. 2014;58(4):443-8. doi: 1O.1097/MPG.0000000000000272.

12. Hoffmann MR, [ackson ST, Iindal K, Senior PA, Mager DR. Vitamin Dstatus, body composition and glycemic control in adults with diabetesand chronic kidney disease. Eur IClin Nutr. 2015;70(6):743-749. doi:1O.1038/ejcn.2015.185.

13. Holick MF, Binkley NC, Bischoff-Ferrari HA, Gordon CM, Hanley DA,Heaney RP, et at. Evaluation, treatment, and prevention of vitamin D defi­ciency: an Endocrine Society clinical practice guideline. IClin EndocrinolMetab. 2011;96(7):1911-30. doi: 10.1210/jc.2011-0385.

14. Aringer M, Kiener HP, Koeller MD, Artemiou 0, Zuckermann A,Wieselthaler G, et al. High turnover bone disease following lung trans­plantation. Bone. 1998;23(5):485-8. doi: 10.1016/S8756-3282(98)00130-6.

15. Mazziotti G, Canalis E, Giustina A. Drug-induced osteoporosis: mechanismsand clinical implications. Am I Med. 2010;123(10):877-84. doi: 10.1016/j.amjmed.20 10.02.028.

16. Mager DR, Alzaben AS, Roberts C, Gilmour SM, Yap). Bone mineral den­sity and growth in children having undergone liver transplantationwith a corticosteroid-free immunosuppressive protocol. JPEN J ParenteralEnteral Nutr. 2015;1-9. doi: 10.1177/0148607115609524.

17. Paccou I. Fardellone P, Cortet B. Cystic fibrosis-related bone disease. CurrOpin Pulm Med. 2013;19(6):681-6. doi: 10.1097/MCP.Ob013e328365ge35.

18. Langlois K, Greene-Finestone L, Little J, Hidiroglou N, Whiting S.Vitamin D status of Canadians as measured in the 2007 to 2009 CanadianHealth Measures Survey. Health Rep. 2010;21(1):47-55.

19. Whiting SJ, Langlois KA, Vatanparast H, Greene-Finestone LS. Thevitamin D status of Canadians relative to the 20 II Dietary ReferenceIntakes: an examination in children and adults with and without supplementuse. Am J Clin Nutr. 2011;94(1):128-35. doi: 1O.3945/ajcn.llI.013268.

20. Wang TK, O'Sullivan 5, Gamble GD, Ruygrok PN. Bone density in heartor lung transplant recipients - a longitudinal study. Transplant Proe.2013;45(6):2357-65. doi: 10.1016/j.transproceed.2012.09.117.