Dietary fatty acids and risk of Alzheimer's disease and related dementias: Observations from the Washington Heights-Hamilton Heights-Inwood Columbia Aging Project (WHICAP)

Introduction:

High dietary intake of long chain, polyunsaturated fatty acids is associated with lower Alzheimer’s disease (AD) risk.

Methods:

Washington Heights-Hamilton Heights-Inwood Columbia Aging Project is a multiethnic, prospective observational study of aging and dementia among elderly (≥ 65 years). Dietary intake was measured using a food frequency questionnaire. Dietary short-, medium-, and long-chain fatty acid intakes were categorized by number of carbons and double bonds. Consensus AD diagnoses were made. Associations between AD risk and dietary fatty acid and cholesterol intakes were estimated using multivariable Cox proportional hazards regression models.

Results:

Of 2612 multiethnic women (67%) and men (baseline age 76.3 [6.4] years), 380 developed AD over an average 4.5 years follow-up. Lower risk of AD was associated with increasing intakes of docosahexaenoic acid (DHA; hazard ratio [HR] = 0.73, 95% confidence interval [CI]: 0.57 to 0.95, P = 0.018) and eicosapentaenoic acid (EPA; HR = 0.74, 95% CI: 0.57 to 0.95, P = 0.021), and longer AD-free survival (P < 0.05).

Discussion:

Higher intake of DHA and EPA are protective for AD.

Adiposity indicators and dementia over 32 years in Sweden

BACKGROUND

High midlife and late-life adiposity may increase risk for dementia. Late-life decrease in body mass index (BMI) or body weight within several years of a dementia diagnosis has also been reported. Differences in study designs and analyses may provide different pictures of this relationship.

METHODS

Thirty-two years of longitudinal body weight, BMI, waist circumference, and waist-to-hip ratio (WHR) data, from the Prospective Population Study of Women in Sweden, were related to dementia. A representative sample of 1,462 nondemented women was followed from 1968 at ages 38-60 years, and subsequently in 1974, 1980, 1992, and 2000, using neuropsychiatric, anthropometric, clinical, and other measurements. Cox proportional hazards regression models estimated incident dementia risk by baseline factors. Logistic regression models including measures at each examination were related to dementia among surviving participants 32 years later.

RESULTS

While Cox models showed no association between baseline anthropometric factors and dementia risk, logistic models showed that a midlife WHR greater than 0.80 increased risk for dementia approximately twofold (odds ratio 2.22, 95% confidence interval 1.00-4.94, p = 0.049) among surviving participants. Evidence for reverse causality was observed for body weight, BMI, and waist circumference in years preceding dementia diagnosis.

CONCLUSIONS

Among survivors to age 70, high midlife waist-to-hip ratio may increase odds of dementia. Traditional Cox models do not evidence this relationship. Changing anthropometric parameters in years preceding dementia onset indicate the dynamic nature of this seemingly simple relationship. There are midlife and late-life implications for dementia prevention, and analytical considerations related to identifying risk factors for dementia.

Microbial-associated oral lichenoid reactions

OBJECTIVE

The objective of the present study was to compare a new type of symptomatic lichenoid reaction, specifically located on the mucosal side of the lips, and associated with microorganisms, with a matched group presenting with reticular oral lichen planus (OLP) of the buccal mucosa.

PATIENTS AND METHODS

The mean age for both groups was 66 years with a predominance of women (62%). The lichenoid reaction group (n = 25) presented with a reticular reaction pattern embracing various degrees of erythema. Patients presenting with OLP had similar lesions confined to the buccal mucosa but not on the mucosal side of the lips.

RESULTS

In both groups, 80% were on any type of medication. However, 56% of the patients with lichenoid reactions medicated with more than three drugs compared with 29% (P < 0.05) in the OLP group. The former group more often used medicaments prescribed for cardiovascular diseases (48%vs 25%). Twenty-two of the patients with lichenoid reactions were treated with chlorhexidine. In 80% of these patients (n = 18), the lesions improved or completely healed, indicating a microbial association.

CONCLUSION

Lichenoid reactions present on the mucosal side of the lips may be initiated by microbial plaque precipitated on the buccal surfaces of the anterior teeth.

Progression of sialadenitis in Sjögren's syndrome

An analysis of progression of sialadenitis in patients with primary and secondary SS has been performed. For this purpose patients were prospectively followed and evaluated with respect to stimulated whole salivary secretion and morphology of labial salivary gland biopsies. Twenty-one patients with primary SS and 18 with secondary SS were followed for a mean of 39 +/- 20 months (range 11-112 months). During this observation period the lymphocytic infiltration in minor salivary glands, measured as focus score, increased in 14/21 (67%) patients with primary SS and in 14/18 (78%) patients with secondary SS. Altogether there was a statistically significant increase in focus score in both primary and secondary SS, but no reduction in salivary production. Consequently, no correlation between changes in focus score and stimulated salivary secretion was found in either primary or secondary SS.

Estrogen accelerates immune complex glomerulonephritis but ameliorates T cell-mediated vasculitis and sialadenitis in autoimmune MRL lpr/lpr mice

Estrogen is known to influence immune responses in healthy subjects in a dichotomous fashion. Thus, in number of previous studies we and others have demonstrated that B cell activities are augmented after exposure to estrogen whereas T cell reactivity is suppressed. Furthermore, it has been shown that this hormone has significant impact on the course of certain human and experimental autoimmune diseases. In this study we report that treatment with physiological doses of estradiol exerts dichotomous effects on different manifestations of the lupus disease in MRL/l mice. On one hand immune complex-mediated glomerulonephritis was significantly accelerated. This outcome was due to polyclonal B cell activation with increased production of antibodies to double-stranded DNA and formation of circulating immune complexes. In contrast, T cell-mediated lesions such as focal sialadenitis, renal vasculitis, and periarticular inflammation were all significantly ameliorated in MRL/l mice exposed to estrogen. Thus, we were able to demonstrate that, within one subject and even within one organ, administration of estrogen leads to differential outcome of SLE morbidity. We propose that the differential effect of estrogen on the manifestations of the autoimmune disease of MRL/l mice is due to its dichotomous effects on B and T cell-mediated immune responses.

Oral lesions of lupus erythematosus patients in relation to other chronic inflammatory oral diseases: an immunologic study

The nature and distribution of mononuclear cells in non-ulcerated oral lesions of discoid (DLE) and systemic lupus erythematosus (SLE), were investigated and compared to other chronic inflammatory oral diseases (lichen planus (LP), contact lesion (CL), unspecified inflammation (UI), geographic tongue (GT), and leukoplakia (LK). For this purpose an immunoperoxidase technique based on staining with monoclonal antibodies was employed. In most LE specimens examined infiltrating cells consisted predominantly of a mixture of T cells (Leu 3a+ and Leu 2a+) that were distributed in the lamina propria, the submucosa, and occasionally also in the epithelium. In general, only few B cells were detected while macrophages were more frequent. In all LE specimens examined beta 2-microglobulin expression was observed on a large proportion of cells including infiltrating mononuclear cells as well as resident keratinocytes. In addition, most infiltrating cells displayed MHC Class II antigens according to a pattern HLA-DR greater than DQ greater than DP. Interestingly, expression of Class II antigens was also observed on epithelial keratinocytes but was restricted to HLA-DR and -DP gene products (DR much greater than DP). HLA-DQ expression was never observed on keratinocytes. In most LE specimens studied a small proportion (less than 5%) of inflammatory cells had detectable interleukin-2 receptors (IL-2R) and/or transferrin receptors (transf-R). However, expression of transf-R was also observed on basal epithelial cells, being more pronounced in DLE than in SLE lesions. The above staining patterns observed in LE lesions, when compared to other chronic inflammatory oral lesions, did not disclose any striking differences that could support the specific diagnosis of LE. However, the findings of Class I and II MHC gene products on oral keratinocytes suggest an important accessory role for these cells in directing the migration of activated lymphoid cells in the epithelium in chronic inflammatory lesions of the oral mucosa.

Effects of immunomodulating treatment on autoimmune sialadenitis in MRL/Mp-lpr/lpr mice

The autoimmune MRL/Mp-lpr/lpr (MRL/l) mouse spontaneously develops sialadenitis with a morphological and phenotypical pattern similar to that seen in human Sjögren's syndrome (SS). This makes the MRL/l mouse a suitable model for therapeutical studies of autoimmune sialadenitis. We have, by histological and immunohistochemical techniques, analyzed the therapeutical effect of treatment with LS2616, a recently synthesized oxokinolinamide derivative, on sialadenitis in submandibular glands of MRL/l mice. The results were compared with effects obtained after treatment with cyclophosphamide (CY) and physiologic saline. Administration of both LS2616 and CY to MRL/l mice has previously been found to result in prolongation of survival and amelioration of organ pathology. However, only CY treatment reduced sialadenitis, while LS2616 increased the semiquantitatively assessed focal inflammation of salivary glands in 6 months old mice. No differences in T-cell phenotypes of infiltrating lymphoid cells in salivary glands between different treatment regims could be noted. However, the frequency of B-cells in the sialadenitis was decreased in the CY treated group. In contrast, CY but not LS2616 treatment normalized expression of T-helper and cytotoxic T-cell phenotypes as well as reduced the B-cell portion in lymph nodes. It is concluded that CY treatment can suppress sialadenitis although both LS2616 and CY are effective in prolongation lifespan of MRL/l mice. This may implicate different immunopathogenic mechanisms for development of sialadenitis versus other organ lesions in the autoimmune disease of MRL/l mice.

Intracranial abscesses in adults: an analysis of 54 consecutive cases

A retrospective analysis was performed of 54 consecutive adult patients with intracranial abscesses hospitalized between 1973 and 1985. Clinical signs and symptoms were varying and no single symptom was found in more than 48% of the patients. Also the laboratory findings were of limited diagnostic value. The etiology of the infections varied with the sources and could be identified in 42 of the patients. In patients with postoperative abscesses or infections after penetrating head injuries Staphylococcus aureus was the most commonly found causative agent. In patients with abscesses originating from sinus, dental or otogenic infections, anaerobic bacteria dominated and most patients had multiple bacterial isolates. A majority of patients (33/47) with diagnosed abscesses were treated with both surgical drainage and systemic antibiotics. 14 patients received antibiotics only, due to inoperable abscesses or spontaneous regression without surgery. 17 of the patients (31.5%) died from their intracranial infections and only 9 survived without sequelae. Important prognostic factors were missed diagnosis and presence of multiple or ruptured abscesses. One patient died of acute brain stem herniation after lumbar puncture, a procedure which was found to be of limited diagnostic value and which seems to be contraindicated in patients with intracranial abscesses.

Expression of HLA-D-locus (DP, DQ, DR)-coded antigens, beta 2-microglobulin, and the interleukin 2 receptor in Sjögren's syndrome

The expression of beta 2-microglobulin (beta 2m), class II major histocompatibility complex (MHC) antigens (HLA-DP, -DQ, -DR) and the interleukin 2 receptor (IL-2R) on resident and infiltrating cells in labial salivary glands of patients with Sjögren's syndrome (SS) was studied using an immunoperoxidase technique based on staining with monoclonal antibodies. The progression of the inflammatory process was accompanied by increasing numbers of immunocompetent cells as well as glandular epithelial cells expressing beta 2m and class II MHC antigens. Up to 60% of the infiltrating lymphocytes were DQ- and DR-positive while fewer cells stained for DP antigen. Glandular epithelium (acinar and ductal cells) stained for products of all three HLA-D subregions but with varying degrees of expression following the pattern DR greater than DP greater than DQ related to the severity of inflammation. A minor portion of the infiltrating lymphocytes expressed IL-2R. These findings emphasize the potential importance of epithelial expression of class II antigens in the local activation of T lymphocytes in salivary gland lesions of SS patients. They also indicate that differences may exist in this respect between T-cell reactions restricted by different class II MHC-encoded gene products.

Immunohistochemical characterization of sialadenitis in NZB X NZW F1 mice

The spontaneously developing sialadenitis in female autoimmune NZB X NZW F1 (NZB/W) mice has been studied with the help of immunohistochemistry and monoclonal antibodies to cell surface antigens. Semiquantitative assessment of stained cells within the infiltrates disclosed a progressive focal inflammation most pronounced in submandibular and parotid glands. The majority of cells expressed Ly-1 (all T cells) and L3T4 (T helper) phenotype, whereas only few Lyt-2 (cytotoxic/suppressor) expressing T cells were seen. A large proportion of the infiltrating cells stained for Ia antigens, which was also found on salivary gland ductal epithelium in the proximity of lymphoid infiltrates. The phenotypic pattern in sialadenitis of NZB/W mice thus closely resembles the pattern previously described for human Sjögren's syndrome (SS). Accordingly, immunomorphological analysis of the NZB/W sialadenitis may be useful in further studies of pathogenesis and therapy of both experimental and human SS.