Diabetes Care
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Published online October 3, 2007
Diabetes Care 31:93-95, 2008
DOI: 10.2337/dc07-0931
© 2008 by the American Diabetes Association
This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF)
Right arrow All Versions of this Article:
dc07-0931v1
31/1/93    most recent
Right arrow Purchase Article
Right arrow View Shopping Cart
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow Request Permissions
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Tao, M.
Right arrow Articles by Eberhardt, M. S.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Tao, M.
Right arrow Articles by Eberhardt, M. S.
Social Bookmarking
Add to CiteULike   Add to Del.icio.us   Add to Digg   Add to Reddit   Add to Technorati  
What's this?

Epidemiology/Health Services Research
Original Research

Relationship of Polyunsaturated Fatty Acid Intake to Peripheral Neuropathy Among Adults With Diabetes in the National Health and Nutrition Examination Survey (NHANES) 1999–2004

Min Tao, MD, PHD1, Margaret A. McDowell, MPH, RD2, Sharon H. Saydah, PHD3 and Mark S. Eberhardt, PHD3

1 Epidemic Intelligence Service Program, Centers for Disease Control and Prevention, Hyattsville, Maryland
2 Division of Health and Nutrition Examination Surveys, National Center for Health Statistics, Hyattsville, Maryland
3 Office of Analysis and Epidemiology, National Center for Health Statistics, Hyattsville, Maryland

Address correspondence and reprint requests to Mark Eberhardt, National Center for Health Statistics, Centers for Disease Control and Prevention, 3311 Toledo Rd., Hyattsville, MD 20782. E-mail: meberhardt{at}cdc.gov


   ABSTRACT
TOP
 ABSTRACT
INTRODUCTION
 RESEARCH DESIGN AND METHODS
 RESULTS
 CONCLUSIONS
 References
 
OBJECTIVE—This study investigated the association between dietary intake of polyunsaturated fatty acids (PUFAs) and peripheral neuropathy in the U.S. population.

RESEARCH DESIGN AND METHODS—We analyzed data from the National Health and Nutrition Examination Survey (NHANES) 1999–2004 for adults ≥40 years of age with diagnosed diabetes, an assessment of peripheral neuropathy, and reliable 24-h dietary recall. The dietary intake of PUFAs was analyzed by peripheral neuropathy status. Multivariate logistic regression models were used to estimate the odds of having peripheral neuropathy in higher quintiles of PUFA intake compared with the lowest quintile.

RESULTS—The mean dietary intake of linolenic acid was 1.25 ± 0.07 g among adults with peripheral neuropathy, significantly lower than the 1.45 ± 0.05 g intake among those without peripheral neuropathy. After controlling for potential confounding variables, adults whose linolenic acid intake was in the highest quintile had lower odds of peripheral neuropathy than adults in the lowest quintile (adjusted odds ratio 0.40 [95% CI 0.21–0.77]).

CONCLUSIONS—Among adults with diagnosed diabetes, dietary intake of linolenic acid is positively associated with lower odds of peripheral neuropathy.

Abbreviations: ALA, {alpha}-linolenic acid • GLA, {gamma}-linolenic acid • NHANES, National Health and Nutrition Examination Survey • PUFA, polyunsaturated fatty acid


   INTRODUCTION
TOP
 ABSTRACT
 INTRODUCTION
RESEARCH DESIGN AND METHODS
 RESULTS
 CONCLUSIONS
 References
 
The prevalence of peripheral neuropathy is 28.5% among adults aged ≥40 years with diabetes in the U.S. population (1). Besides improving glycemic control, few available therapeutic choices for peripheral neuropathy can influence its natural history (2). Identification of additional modifiable factors that may be related to the progression of peripheral neuropathy is important. This study investigated whether dietary polyunsaturated fatty acid (PUFA) intake is associated with measured peripheral neuropathy.


   RESEARCH DESIGN AND METHODS
TOP
 ABSTRACT
 INTRODUCTION
 RESEARCH DESIGN AND METHODS
RESULTS
 CONCLUSIONS
 References
 
This study used data from the National Health and Nutrition Examination Survey (NHANES) 1999–2004. The sample includes 1,062 adults ≥40 years of age with self-reported diagnosed diabetes, peripheral neuropathy measurement, and complete and reliable 24-h dietary recall data.

Measurements of peripheral neuropathy
Peripheral neuropathy was assessed by testing foot sensation using a 5.07-gauge Semmes-Weinstein nylon monofilament (3). Three plantar metatarsal sites (hallux and first and fifth metatarsal heads) were tested on each foot in random order. Peripheral neuropathy was defined as having one or more insensate sites (1).

Assessment of PUFA intake
Dietary nutrient intake estimates were obtained from a single in-person interview of 24-h dietary intake. The NHANES data files include energy intake, total PUFA intake, and intake of seven specific fatty acids (C18:2, C18:3, C18:4, C20:4, C20:5, C22:5, and C22:6). Total long-chain PUFA intake was calculated by summing intake of PUFAs with ≥20 carbon atoms. Use of dietary supplements containing PUFA in the past 30 days was ascertained during the household interview (4).

Covariates
The analysis controlled for previously reported risk factors (5–7), namely self-reported age, sex, race/ethnicity, education, smoking status, duration of diabetes, and measured weight, height, blood pressure, and glycohemoglobin (A1C) (8,9). High blood pressure was defined as average systolic blood pressure ≥140 mmHg or average diastolic blood pressure ≥90 mmHg. Poor glycemic control was defined as A1C ≥7% (10).

Statistics
Descriptive statistics on the dietary intake of PUFAs and other characteristics were calculated. Student's t test or {chi}2 test was used separately for continuous or categorical variables.

The percentages of adults with peripheral neuropathy in each quintile of PUFA intake were reported. {chi}2 test was used to test whether the percentage of people with peripheral neuropathy differs by quintiles of PUFA intake. A logistic regression model was used to estimate the odds of having peripheral neuropathy among adults in higher PUFA intake quintiles relative to adults in the lowest PUFA intake quintile (Q1), first adjusting for energy intake and then further adjusting for previously identified covariates. Analyses were conducted using SUDAAN 9.0 (11).


   RESULTS
TOP
 ABSTRACT
 INTRODUCTION
 RESEARCH DESIGN AND METHODS
 RESULTS
CONCLUSIONS
 References
 
Adults with peripheral neuropathy were significantly older, taller, and more likely to be male and had lower education and longer duration of diabetes than adults without peripheral neuropathy.

Among adults with peripheral neuropathy, the mean daily total PUFA intake was 14.60 ± 0.79 g and the mean daily intake of linolenic acid (C18:3) was 1.25 ± 0.07 g, significantly lower than the 16.82 ± 0.59 and 1.45 ± 0.05 g respective values among adults without peripheral neuropathy. Intake of other PUFAs was not statistically different by peripheral neuropathy status.

Relative to adults in Q1 of total PUFA intake, the odds of having peripheral neuropathy was 0.43 (95% CI 0.19–1.00) for adults in Q5 after adjusting for previously identified covariates (Table 1). Relative to adults in Q1 of C18:3 intake, the odds of having peripheral neuropathy was 0.54 (0.30–0.99) for adults in Q4 and 0.40 (0.21–0.77) for adults in Q5. Logistic models including and excluding diabetes duration had virtually identical findings, suggesting that diabetes duration does not change the association between PUFA intake and peripheral neuropathy.


View this table:
[in this window]
[in a new window]

  		Table 1— Percent with peripheral neuropathy and the odds of having peripheral neuropathy by quintile of total PUFA intake and linolenic acid (C18:3) intake in adults with diagnosed diabetes aged ≥40 years, NHANES 1999–2004

 
Only 4.04% of adults reported taking supplements containing PUFAs. The association between taking supplements containing PUFAs and the risk of peripheral neuropathy was not estimated because of small sample size. Inclusion of supplement usage in regression models did not affect the association between dietary PUFA intake and peripheral neuropathy.


   CONCLUSIONS
TOP
 ABSTRACT
 INTRODUCTION
 RESEARCH DESIGN AND METHODS
 RESULTS
 CONCLUSIONS
References
 
This is the first study to explore whether high dietary PUFA intake is associated with lower risk of peripheral neuropathy. We found that dietary intake of linolenic acid C18:3 (undifferentiated) is negatively associated with the odds of peripheral neuropathy among adults with diabetes. Studies have shown that {gamma}-linolenic acid (C18:3 n-6) (GLA) supplements have a protective effect on diabetic peripheral neuropathy (12–14). However, GLA is seldom found in foods. The major form of C18:3 in food is {alpha}-linolenic acid (C18:3 n-3) (ALA). Thus, it is reasonable to expect that the negative association between C18:3 and peripheral neuropathy in this study is due to ALA.

No study has examined the association between ALA and diabetic peripheral neuropathy. However, high dietary intake of ALA was found to reduce the risk of coronary heart disease (15–17) and to be associated with lower risk for hypertension (18). Vascular factors are important in the pathogenesis of peripheral neuropathy (2,19). The protective effect of ALA on macrovascular diseases and its association with diabetic peripheral neuropathy may be due to similar biological mechanisms.

One limitation of this study is that the PUFA intake was classified based on a single 24-h dietary recall. Due to daily variation in dietary intake, adults may be misclassified with respect to their usual PUFA intake, but the effect seems to be random across the groups. In NHANES, only tactile peripheral neuropathy is measured, and the association of PUFAs to other sensory functions, such as temperature sensitivity, cannot be considered. However, monofilament is an inexpensive and well-accepted tool for measuring peripheral neuropathy. It has a sensitivity of 85–100% and specificity of 76% in predicting foot ulcer (20).

Identification of prevention methods for peripheral neuropathy can help reduce the prevalence of peripheral neuropathy and its complications. More work is needed to study the association between ALA and peripheral neuropathy reported here and to clarify the biological mechanisms.


   Footnotes
 
Published ahead of print at http//:care.diabetesjournals.org on 3 October 2007. DOI: 10.2337/dc07-0931.

A table elsewhere in this issue shows conventional and Système International (SI) units and conversion factors for many substances.

The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C Section 1734 solely to indicate this fact.

Received for publication June 2, 2007. Accepted for publication October 1, 2007.


   References
TOP
 ABSTRACT
 INTRODUCTION
 RESEARCH DESIGN AND METHODS
 RESULTS
 CONCLUSIONS
 References
 

  1. Gregg EW, Sorlie P, Paulose-Ram R, Gu Q, Eberhardt MS, Wolz M, Burt V, Curtin L, Engelgau M, Geiss L: Prevalence of lower-extremity disease in the U.S. adult population ≥40 years of age with and without diabetes: 1999–2000 National Health and Nutrition Examination Survey. Diabetes Care 27:1591–1597, 2004[Abstract/Free Full Text]
  2. Boulton AJ, Malik RA, Arezzo JC, Sosenko JM: Diabetic somatic neuropathies. Diabetes Care 27:1458–1486, 2004[Free Full Text]
  3. National Health and Nutrition Examination Survey: Lower Extremity Disease Procedures Manual. Hyattsville, MD, National Center for Health Statistics, 1999
  4. National Center for Health Statistics: NHANES data files. Available from http://www.cdc.gov/nchs/about/major/nhanes/datalink.htm. Accessed 6 February 2007
  5. Tesfaye S, Stevens LK, Stephenson JM, Fuller JH, Plater M, Ionescu-Tirgoviste C, Nuber A, Pozza G, Ward JD: Prevalence of diabetic peripheral neuropathy and its relation to glycaemic control and potential risk factors: the EURODIAB IDDM Complications Study. Diabetologia 39:1377–1384, 1996[Medline]
  6. Cheng YJ, Gregg EW, Kahn HS, Williams DE, De Rekeneire N, Narayan KM: Peripheral insensate neuropathy–a tall problem for US adults? Am J Epidemiol 164:873–880, 2006[Abstract/Free Full Text]
  7. Sorensen L, Molyneaux L, Yue DK: Insensate versus painful diabetic neuropathy: the effects of height, gender, ethnicity and glycaemic control. Diabetes Res Clin Pract 57:45–51, 2002[Medline]
  8. National Health and Nutrition Examination Survey: physician examination procedures manual. National Center for Health Statistics, 2003. Available from http://www.CDC.GOV/nchs/data/nhanes/nhanes_03_04/PE.pdf. Accessed 6 February 2007
  9. National Health and Nutrition Examination Survey: MEC Laboratory Component: Glycohemoglobin. Hyattsville, MD, National Center for Health Statistics, 2006
  10. American Diabetes Association: Standards of medical care in diabetes—2007 (Position Statement). Diabetes Care 30(Suppl. 1):S4–S41, 2007
  11. Research Triangle Institute: SUDAAN Language Manual. Release 9.0. Research Triangle Park, NC, Research Triangle Institute, 2004
  12. Head RJ, McLennan PL, Raederstorff D, Muggli R, Burnard SL, McMurchie EJ: Prevention of nerve conduction deficit in diabetic rats by polyunsaturated fatty acids. Am J Clin Nutr 71:386S–392S, 2000[Abstract/Free Full Text]
  13. Keen H, Payan J, Allawi J, Walker J, Jamal GA, Weir AI, Henderson LM, Bissessar EA, Watkins PJ, Sampson M: Treatment of diabetic neuropathy with {gamma}-linolenic acid: the {gamma}-Linolenic Acid Multicenter Trial Group. Diabetes Care 16:8–15, 1993[Abstract]
  14. Jamal GA: The use of gamma linolenic acid in the prevention and treatment of diabetic neuropathy. Diabet Med 11:145–149, 1994[Medline]
  15. de Lorgeril M, Salen P, Martin JL, Monjaud I, Delaye J, Mamelle N: Mediterranean diet, traditional risk factors, and the rate of cardiovascular complications after myocardial infarction: final report of the Lyon Diet Heart Study. Circulation 99:779–785, 1999[Abstract/Free Full Text]
  16. Singh RB, Dubnov G, Niaz MA, Ghosh S, Singh R, Rastogi SS, Manor O, Pella D, Berry EM: Effect of an Indo-Mediterranean diet on progression of coronary artery disease in high risk patients (Indo-Mediterranean Diet Heart Study): a randomised single-blind trial. Lancet 360:1455–1461, 2002[Medline]
  17. Mozaffarian D, Ascherio A, Hu FB, Stampfer MJ, Willett WC, Siscovick DS, Rimm EB: Interplay between different polyunsaturated fatty acids and risk of coronary heart disease in men. Circulation 111:157–164, 2005[Abstract/Free Full Text]
  18. Djousse L, Arnett DK, Pankow JS, Hopkins PN, Province MA, Ellison RC: Dietary linolenic acid is associated with a lower prevalence of hypertension in the NHLBI Family Heart Study. Hypertension 45:368–373, 2005[Abstract/Free Full Text]
  19. Cameron NE, Eaton SE, Cotter MA, Tesfaye S: Vascular factors and metabolic interactions in the pathogenesis of diabetic neuropathy. Diabetologia 44:1973–1988, 2001[Medline]
  20. Mayfield JA, Sugarman JR: The use of the Semmes-Weinstein monofilament and other threshold tests for preventing foot ulceration and amputation in persons with diabetes. J Fam Pract 49:S17–S29, 2000[Medline]

Add to CiteULike CiteULike   Add to Del.icio.us Del.icio.us   Add to Digg Digg   Add to Reddit Reddit   Add to Technorati Technorati    What's this?



This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF)
Right arrow All Versions of this Article:
dc07-0931v1
31/1/93    most recent
Right arrow Purchase Article
Right arrow View Shopping Cart
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow Request Permissions
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Tao, M.
Right arrow Articles by Eberhardt, M. S.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Tao, M.
Right arrow Articles by Eberhardt, M. S.
Social Bookmarking
Add to CiteULike   Add to Del.icio.us   Add to Digg   Add to Reddit   Add to Technorati  
What's this?

HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Diabetes Diabetes Care Clinical Diabetes Diabetes Spectrum