Author’s affiliation:

Abstract

Another reason is the deregulation in the production of cytokines, due to fat excess, that increases a state of chronic inflammation that leads to insulin resistance.¹³ There is a consensus about waist circumference measurement as a indirect indicator of presence of intraabdominal fat. It’s easy to obtain and have a low cost, sue to this, it is used to predict early the risk of diseases such as diabetes mellitus, hypertension and cardiovascular diseases, and provides useful information to identify the risk population, even before the obesity is identify with BMI (Body Mass Index).^14,15 However, for this measurement to be useful and reliable, it is necessary the existence of measurement and standardization protocols to the staff that performed this measurements, in order to avoid errors that could affect the risk classification with the obtained data.¹⁶

There are various criteria to evaluate the risk of cardiovascular diseases, in relation to the value of abdominal circumference; the Adult Panel Treatment III (APT-III) established a values of ≥80cm in women and ≥94cm in men, to define abdominal obesity or incremented risk.^9,17,18 The International Diabetes Federation (IDF) established values of ≥90cm in men and ≥80cm in women.¹⁹ In 1997, World Health Organization (WHO) proposed cut points to identify people in risk into three categories, “very low” ≤79cm in women and ≤93cm in men; “incremented risk” from 80 to 87cm in women and from 94 to 101cm in men, and “high risk” ≥ 88 cm in women and ≥102cm in men.²⁰ There is controversy over appropriate cut values for different ethnic groups.^9,16

In Costa Rica, the indication for measurement of waist circumference is establish in guides for the attention of diabetic and hypertensive individuals.²¹ However, it is not considered as a primary care activity in Basic Health Care Crew (Equipos Básicos de Atención en Salud -EBAIS), with an essential function in health promotion and disease prevention. Each EBAIS is composed of a doctor, a nurse and a primary health care technician (ATAP); distributed over the country and attends from 3500 to 5000 habitants each.²¹ Due to this, an opportunity was identify to include the measurement of waist circumference in daily routine activities of ATAP’s during home visits, in order to identify the population in risk and refer them to local interventions in health prevention and promotion.

The objective of this article is to describe the characteristics of the population in Santa Ana Health Care Area, to whom the waist circumference were taken and stratification according to the risk of cardiovascular diseases was made.

Methodology

Cross-section descriptive studies made in January 2009 and December 2010 in Santa Ana Health Care Area, Costa Rica, integrated by 10 EBAIS. Adult men and women were evaluated in age ranges from 20 to 44 years old, usual residents that were found at home during home visit by ATAP’s performed between 7am to 12md. Pregnant women, women in 4 months postpartum period, posterior to abdominal surgery or with some kind of physical disability that made measurement impossible.

ATAP’s were trained and standardized in the process of measurement based on “manual de procedimiento para la medición de la circunferencia abdominal” (Waist circumference measurement procedure manual), designed with this purpose.²¹ Fiberglass, inextensible measurement tapes, graduated in centimeters, and sensible to millimeters, calibrated by Costa Rican Measurements Laboratory (LACOMET, certified number 22010109).

The analyzed variables were: age in years, genre, level of schooling, occupation and waist circumference; and WHO classification was used.²⁰ The occupation of remunerated activities were classified according to the International Labour Organization (ILO).²³ Descriptive statistics and the analysis of the association of different variables with the level of risk were made with SPSS program, ver. 15.0 for Windows. The level of statistical significance was of p<0,05.

Results

The results of 325 people, 76,9% were women, with an average age of 30±6,5 years, similar in both genre. 74,2% of the population were under 35 years old. According to the level of schooling, 40,9% of the population had primary education (complete or incomplete), 46,1% had middle education (complete or incomplete), 11,1% had college studies and 1,8% were illiterate. 50,1% were housewives, and 47,7% had remunerated activities, mainly services, commerce, operator workers and artisans; 72,6% of the population were married or live in cohabitation.

The average waist circumference measurement in women was of 86,4±12,4cm, and of 88,1±11,5cm in men. There was no statistical significance between waist circumference means by genre (p=0,282). There was an increase of waist circumference in women according to age, up to 39 years old, with and statistical significant differences (p= 0,03); in men, there was no ascendant change in age groups, but it was statistically significant (p=0,04). (Table 1).

According to WHO cut points, 57,5% (n=187), the population was classified with some risk degree (intermediate and high risks). From these percentage, 35,1% with high risks (43,2% women and 8% men) (Table 2).

The percentage of population in “high risk” category had increase in each age group especially in women, however, the major change in prevalence was in age group between 20-24 years old and 25-29 years old (Figure 1). In men, the most prevalent age group accounting for 85% (n=5) was that of ages 35-39. Excluding low risk individuals, an average waist circumference in women in all age groups was over 88cm and in men, only age group between 25-29 years old were over 102cm, placing them in high risk category (Table 3).

Discussion

Waist circumference is a easy to determine tool and of great use in clinical practice, and as a product of study, the measurement of the waist circumference was included in health promotion and prevention in primary care attention.

The population in this study was characterized with a majority of individuals being young women, with level of schooling no higher than middle school, and housewives, indicators of low socioeconomically status. Also, the waist circumference placed them in risk of diseases such as diabetes and hypertension; the results on other studies indicate that obesity problems is a higher and more accentuated in low socioeconomically status.^{24, 25} The profile of individuals in this study, in addition to high values of waist circumference, can explain the high prevalence of diabetes in women in Costa Rica, shown in national surveys.^{3, 4}

A survey of “diabetes, hypertension and risk factors for chronic diseases” performed in 2004, used WHO waist circumference risk factors values, that showed a group with ages between 20-39, and a prevalence of 44,8% in women and 17% in men.3, 4 In this study, the prevalence in women was similar (43%), but lower in men (8%). Excluding all individuals without risk factors, the waist circumference risk value exceeded in all age groups, especially groups between 20-24 years old and 25-29 years old, suggesting that prevention measurements for cardiovascular diseases should be prioritize in younger groups, in order to prevent the onset of diseases, and abdominal fat between genre vary, being higher in women.24 Among older women, an increase in androgyny, shown by levels of testosterone, produce an accumulation of abdominal adipose tissue, that increases the activity of hepatic lipase, and decrease consequently the levels of HDL, making waist circumference a simple indicator to evaluate lipid metabolism in primary care.^{18, 26}

International organizations (APT, ADF and WHO) use different criteria to classify population in risk, concurring with the cut point of 80cm in women, but not in men. Many authors recommend reevaluate the cut values of 102cm in men, in order to avoid lately interventions; so that in this study 19 more men could be classify in the risk category according to IDF. ^9,27

One limitation in these results is that the type of population were found in households were not representative of the general population, since visiting hours were made in the morning, family members that were not at home were especially men. The limitation were for all activities in home visits, therefore other strategies must be sought to capture this population, and a possible site would be the local job centers.

In conclusion, this indicator is practical, non invasive, and accepted by all users and health care givers, and it can be used in prevention at community level;²⁸ it allowed the identification of population in risk, that due to a younger age were not in demand for cardiovascular diseases, but could be include in local interventions in health promotion and prevention in primary care attention.

Acknowlegments: to the staff of COOPESANA R.L. (Santa Ana Health Corporation), especially to ATAP’s that recollected all data. To Dr. Hilda Núñez Rivas for her technical support in this project.

References