Transcript Alternate Mediterranean Diet score

Journal Club
Rawlings AM, Sharrett AR, Schneider AL, Coresh J, Albert M, Couper D,
Griswold M, Gottesman RF, Wagenknecht LE, Windham BG, Selvin E.
Diabetes in midlife and cognitive change over 20 years: a cohort study.
Ann Intern Med. 2014 Dec 2;161(11):785-93.
Crous-Bou M, Fung TT, Prescott J, Julin B, Du M, Sun Q, Rexrode KM, Hu
FB, De Vivo I.
Mediterranean diet and telomere length in Nurses' Health Study:
population based cohort study.
BMJ. 2014 Dec 2;349:g6674. doi: 10.1136/bmj.g6674.
2014年12月18日 8:30-8:55
８階 医局
埼玉医科大学 総合医療センター 内分泌・糖尿病内科
Department of Endocrinology and Diabetes,
Saitama Medical Center, Saitama Medical University
松田 昌文
Matsuda, Masafumi
the Departments of Medicine (P.K.C., W.M., E.B.L.), Psychiatry and Behavioral Sciences
(G.L.), Pathology (T.J.M.), and Psychosocial and Community Health (S.M.M.), University of
Washington; the Group Health Research Institute (R.W., R.A.H., E.B.L.); the Department of
Medicine, VA Puget Sound Health Care System and University of Washington (S.E.K.); and
the Swedish Neuroscience Institute ( J.D.B.) — all in Seattle; the Diabetes Center and
Department of Medicine (D.M.N.) and the Biostatistics Center (H.Z.), Massachusetts General
Hospital and Harvard Medical School; and the Department of Biostatistics, Harvard School
of Public Health (S.H.) — all in Boston; and the Department of Internal Medicine, Wake
Forest School of Medicine, Winston-Salem, NC (S.C.).
N Engl J Med 2013;369:540-8. DOI: 10.1056/NEJMoa1215740
Figure 1. Risk of Incident Dementia Associated with the Average Glucose Level
during the Preceding 5 Years, According to the Presence or Absence of Diabetes.
Solid curves represent estimates of the hazard ratios for the risk of incident dementia
across average glucose levels relative to a reference level of 100 mg per deciliter for
participants without diabetes (Panel A) and 160 mg per deciliter for participants with
diabetes (Panel B). The dashed lines represent pointwise 95% confidence intervals. To
convert the values for glucose to millimoles per liter, multiply by 0.05551.
N Engl J Med 2013;369:540-8.
Johns Hopkins Bloomberg School of Public Health and Johns Hopkins University
School of Medicine, Baltimore, Maryland; University of North Carolina, Chapel Hill,
North Carolina; University of Mississippi Medical Center, Jackson, Mississippi;
and Wake Forest University, Winston-Salem, North Carolina.
Ann Intern Med. 2014 Dec 2;161(11):785-93.
Background: Type 2 diabetes is associated with
dementia risk, but evidence is limited for possible
associations of diabetes and prediabetes with
cognitive decline.
Objective: To determine whether diabetes in
midlife is associated with 20-year cognitive
decline and to characterize long-term cognitive
decline across clinical categories of hemoglobin
A1c (HbA1c) levels.
Design: Prospective cohort study.
Setting: The community-based ARIC
(Atherosclerosis Risk in Communities) study.
Participants: 13 351 black and white adults aged
48 to 67 years at baseline (1990 to 1992).
Measurements: Diabetes was defined by selfreported physician diagnosis or medication use or
HbA1c level of 6.5% or greater. Undiagnosed
diabetes, prediabetes, and glucose control in
persons with diagnosed diabetes were defined by
clinical categories of HbA1c level. Delayed word
recall, digit symbol substitution, and word fluency
tests were used to assess cognitive performance
and were summarized with a global Z score.
Delayed word recall, digit symbol substitution, and word fluency tests
We used 3 neuropsychological tests to assess cognitive function: the delayed
word recall test (DWRT) (17), the digit symbol substitution test (DSST) of the
Wechsler Adult Intelligence Scale-Revised (18), and the word fluency test
(WFT) (19).
Protocols for the tests were standardized, and trained examiners administered
the tests in a fixed order during 1 session in a quiet room.
The DWRT is a test of verbal learning and recent memory. Participants were
asked to learn 10 common nouns by using each in a sentence. Two exposures
to each word were given. After a 5-minute filled delay, participants had 60
seconds to recall the words. The score was equal to the number of words
recalled.
The DSST is a test of executive function and processing speed. In this 90second test, participants were asked to use a key to translate numbers to
symbols. The score was equal to the count of numbers correctly translated to
symbols, with possible scores ranging from 0 to 93.
The WFT is a test of executive function and language. Participants were given
60 seconds for each of the letters “F,” “A,” and “S” and were asked to generate
as many words as possible beginning with each letter, excluding proper nouns.
The score was equal to the total number of words generated for each letter.
•A z-score is calculated for a single value and indicates the distance of that value from the
mean in units of standard deviations;
•A positive z-score indicates that the value is above the mean;
•A negative z-score indicates that the value is below the mean;
•z can be any whole number or a fraction, so z = 3, z = 1.3 or z = 0.5 are all valid.
A composite global cognitive Z score was calculated by averaging the Z scores of
the 3 tests and was then standardized to visit 2 by using the mean and SD of the
global Z scores at visit 2.
Results: Diabetes in midlife was associated with a 19%
greater cognitive decline over 20 years (adjusted global
Z-score difference, −0.15 [;95% CI, −0.22 to −0.08];)
compared with no diabetes. Cognitive decline was
significantly greater among persons with prediabetes
(HbA1c level of 5.7% to 6.4%) than among those with an
HbA1c level less than 5.7%. Participants with poorly
controlled diabetes (HbA1c level ≥7.0%) had greater
decline than those whose diabetes was controlled
(adjusted global Z-score difference, −0.16; P = 0.071).
Longer-duration diabetes was also associated with
greater late-life cognitive decline (P for trend < 0.001).
Rates of decline did not differ significantly between white
and black persons (P for interaction = 0.44).
Limitation: Single HbA1c
measurement at baseline, 1 test per
cognitive domain, and potential
geographic confounding of race
comparisons.
Conclusion: Diabetes prevention and
glucose control in midlife may protect
against late-life cognitive decline.
Primary Funding Source: National
Institutes of Health.
Message
動脈硬化リスク研究・ARIC試験参加の48-67歳の
成人1万3351人を対象に、中年期の糖尿病（DM）
と20年間での認知機能低下度の関連を検証。中
年期のDM罹患者は非罹患者に比べ19％の認知機
能低下度増加と関連し、血糖コントロール不良
DM患者群では良好群に比べ認知機能低下度が増
加した（調整後Zスコア差－0.15、－0.16）。
A telomere is a region of repetitive nucleotide sequences at each end of a
chromatid, which protects the end of the chromosome from deterioration or from
fusion with neighbouring chromosomes. Its name is derived from the Greek
nouns telos (τέλος) 'end' and merοs (μέρος, root: μερ-) 'part.' For vertebrates, the
sequence of nucleotides in telomeres is TTAGGG.
During chromosome replication, the enzymes that duplicate DNA cannot continue
their duplication all the way to the end of a chromosome, so in each duplication
the end of the chromosome is shortened[1] (this is because the synthesis of
Okazaki fragments requires RNA primers attaching ahead on the lagging strand).
The telomeres are disposable buffers at the ends of chromosomes which are
truncated during cell division; their presence protects the genes before them on
the chromosome from being truncated instead.
Over time, due to each cell division, the telomere ends become shorter.[2] They
are replenished by an enzyme, telomerase reverse transcriptase.
Human
chromosomes
(grey) capped by
telomeres (white)
Objective
To examine whether adherence to the
Mediterranean diet was associated with longer
telomere length, a biomarker of aging.
Design Population based cohort study.
Setting Nurses’ Health Study, an ongoing prospective
cohort study of 121 700 nurses enrolled in 1976; in
1989-90 a subset of 32 825 women provided blood
samples.
Participants 4676 disease-free women from nested
case-control studies within the Nurses’ Health Study
with telomere length measured who also completed
food frequency questionnaires.
Main outcome measure Association between relative
telomere lengths in peripheral blood leukocytes
measured by quantitative real time polymerase chain
reaction and Alternate Mediterranean Diet score
calculated from self reported dietary data.
Trichopoulou adapted the Alternate Mediterranean Diet score from the Mediterranean Diet Score to
assess adherence to the traditional Mediterranean diet.2 The Alternate Mediterranean Diet score
includes the following nine components: vegetables (excluding potatoes), fruits, nuts, whole grains,
legumes, fish, monounsaturated:saturated fatty acid ratio, red and processed meats, and moderate
alcohol intake. The possible score range is 0-9, with a higher score representing a closer
resemblance to the Mediterranean diet. We dichotomized each of the nine dietary components at
the median. We gave participants with intake above the median 1 point each for vegetables, fruits,
nuts, whole grains, legumes, fish, and monounsaturated:saturated fatty acid ratio; we scored intake
equal to or below the median as 0 points for each component. We scored red and processed meat
consumption below the median as 1 point, with 0 points for intake equal to or above the median.
Participants received 1 point for alcohol intake between 5 and 15 g/day; otherwise, they got 0 points.
Details of the Alternate Mediterranean Diet scoring system are described elsewhere.3
We used principal component analysis of the food frequency questionnaires to identify prudent and
Western dietary patterns.30 31 The prudent dietary pattern is characterized by high intakes of fruits,
vegetables, legumes, fish and other seafood, poultry, and whole grains; the Western dietary pattern
includes high intakes of red and processed meats, butter, high fat dairy products, eggs, sweets and
desserts, French fries, and refined grains. Details of the reproducibility and validity of dietary
patterns assessed with a food frequency questionnaire have been previously described.30 31
The Alternative Healthy Eating Index measures adherence to a dietary pattern based on foods and
nutrients most predictive of risk for chronic disease in the literature.32 The Alternative Healthy
Eating Index ranges from 0 to 110 points. Each of the 11 components of the score (vegetables,
fruits, whole grains, sugar sweetened drinks, nuts and legumes, red and processed meat, trans fat,
long chain (n-3) fats, polyunsaturated fatty acids, sodium, and alcohol) has a minimum score of 0
(worst) and a maximum score of 10 (best), according to component specific criteria reflecting either
the current dietary guidelines or associations reported in the literature. Details of component
selection and Alternative Healthy Eating Index calculation have been previously described.32
Table 3| Estimated least squares mean telomere length z scores (and
standard errors) by Mediterranean diet score categories (Alternate
Mediterranean Diet score) in Nurses’ Health Study (n=4676)
Results
Greater adherence to the Mediterranean
diet was associated with longer telomeres
after adjustment for potential confounders.
Least squares mean telomere length z
scores were −0.038 (SE 0.035) for the
lowest Mediterranean diet score groups and
0.072 (0.030) for the highest group (P for
trend=0.004).
Conclusion
In this large study, greater adherence to the
Mediterranean diet was associated with longer
telomeres. These results further support the
benefits of adherence to the Mediterranean diet
for promoting health and longevity.
Message
看護師健康調査に参加した無疾患の女性4676人
を対象に、地中海食の順守と老化の指標テロメ
ア長との関連を集団ベースのコホート研究で検
討。潜在的交絡因子で調整後、地中海食の順守
はテロメア長の伸長と関連した。テロメア長最
小二乗平均値のzスコアは地中海食スコア最低群
で－0.038、最高群で0.072だった（傾向のＰ＝
0.004）。