JP2011056139A - Method of measuring body fat of cat - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of accurately measuring the body fat of a cat. <P>SOLUTION: In this method of measuring the body fat of a cat, the thickness of fat of any region or its lower tissue from the back of a neck to a scapula in the cat in a face down posture is measured, and the body fat of the whole body is obtained based on the thickness. Preferably the thickness is measured by biological impedance, electrostatic capacity, ultrasonic wave, infrared ray, CT or MRI. Further preferably the body fat of the whole body is obtained based on the weight of the cat. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for measuring cat body fat.

  Obesity is widely recognized in cats raised as pets due to the rich food situation in recent years. In one study, 25-30% of cats are considered obese or overweight (see Non-Patent Document 1). Obese cats are said to have a high risk of causing diabetes, skin diseases, fatty liver, etc., and are a great threat to the health and well-being of cats.

  Body fat is a measure of whether or not you are obese. Regarding the measurement of body fat, the applicant has previously proposed a device for obtaining human body fat by measuring bioimpedance (see Patent Document 1). There is also known an impedance measuring instrument in which a method for measuring body fat by a bioimpedance method for humans is applied to livestock such as cattle that are animals (see Patent Document 2).

  The applicant has also proposed a body fat measurement method for dogs (see Patent Document 3). In this method, the body impedance is measured by using a body fat measuring tool and pressing the electrode body of the measuring tool around the last rib of the dog. Then, body fat is calculated based on the measured bioelectrical impedance. According to this method, the body fat of a dog can be measured very easily and accurately.

  When a dog is a measurement target, as described in Patent Document 3, it is advantageous from the viewpoint of measurement accuracy that the bioelectrical impedance is measured by selecting the peripheral portion of the last rib as a target site. However, since the distribution of subcutaneous fat is often different from animal to animal, if the animal whose distribution of body fat is significantly different from that of the dog is to be measured, the area around the last rib is selected as the target region. However, body fat may not be measured accurately. For example, unlike dogs, cats hardly see subcutaneous fat around the last rib, so it is not easy to accurately measure cat body fat in the same way as dogs.

JP 2002-369806 A JP 2002-253523 A Japanese Patent No. 4342581

Scarlett JM, Donoghue S, Daidla J, et. Al., "Overweight cats: prevalence and risk factors", Int. J. Obes., 1994, 18, s22-s28

  The subject of this invention is providing the method of measuring the body fat of a cat more correctly than before.

  The present invention measures the thickness of the subcutaneous fat or the lower tissue of any part between the dorsal neck of the prone cat and between the shoulder ribs, and determines the body fat of the whole body based on the thickness. A method for measuring body fat of a cat is provided.

  The present invention also provides a method for measuring the body fat percentage of a cat, wherein the body fat percentage is determined by measuring the bioimpedance between the back of the neck and the shoulder ribs in a prone cat.

  According to the method of the present invention, the body fat of a cat can be accurately measured.

FIG. 1 is a schematic diagram showing the state of a cat when carrying out the measuring method of the present invention. 2 (a) and 2 (b) are graphs showing the relationship between the bioelectrical impedance and the thickness of subcutaneous fat, FIG. 2 (a) is the result according to the present invention, and FIG. 2 (b) is a comparative example. Is the result of FIG. 3 (a) is a graph showing the relationship between the whole body fat percentage measured according to the present invention and the thickness of subcutaneous fat, and FIG. 3 (b) shows the whole body fat percentage measured according to the present invention and the bioimpedance. It is a graph which shows the relationship. FIG. 4A is a graph showing the relationship between the whole body fat percentage and the thickness of subcutaneous fat in the comparative example, and FIG. 4B is a graph showing the relation between the whole body fat percentage and the bioelectrical impedance in the comparative example. is there. FIG. 5 is a perspective view showing an example of an apparatus used for measuring bioimpedance. FIG. 6 is a schematic diagram showing a bioimpedance measurement method using the apparatus shown in FIG.

  The present invention will be described below based on preferred embodiments with reference to the drawings. The term “body fat” in the body fat measurement method of the present invention is a concept including both “body fat percentage” and “body fat mass (weight, volume)” unless otherwise specified.

  In the present invention, the body fat of a cat is measured in a state where the cat is prone as shown in FIG. The reason for prone to cats is to ensure measurement stability and reproducibility. Then, under the prone state, the thickness of the subcutaneous fat or its lower tissue in any part between the back of the neck along the midline and between the shoulder ribs is measured. The measurement site is the site indicated by A in FIG. In the following description, this measurement site A is also simply referred to as “between shoulder and ribs” for convenience. In addition, in the same figure, a pair of curved line represented with a dotted line has shown the site | part in which the edge of a shoulder rib is located. As a result of the study by the present inventors, compared with dogs, cats have relatively thick subcutaneous fat between the back of the neck and between the shoulder ribs, and when measuring body fat at this site, accurate measurement results can be obtained. It turned out to be obtained.

  The thickness of the subcutaneous fat and / or the underlying tissue between the shoulder ribs may be measured by picking the skin between the shoulder ribs and using a caliper or the like, or indirectly using a predetermined method described later, And you may measure noninvasively. The lower tissue of subcutaneous fat includes, for example, fat and tissue fluid. For convenience, in the following description, unless otherwise specified, subcutaneous fat and / or its lower tissue is collectively referred to as subcutaneous fat.

  When the thickness of the subcutaneous fat is indirectly measured using a predetermined means instead of actual measurement, examples of the means include bioimpedance, capacitance, ultrasonic waves, infrared rays, and CT (Computed Tomography). Alternatively, noninvasive measurement means such as MRI (Nuclear Magnetic Resonance Image) can be used. These may be used alone or in combination of two or more.

  In order to determine the thickness of subcutaneous fat from the measurement of bioimpedance, the impedance between the shoulder ribs is measured using an impedance measurement device, and the thickness can be obtained from a calibration curve between the impedance obtained beforehand and the thickness of subcutaneous fat. That's fine. To obtain the thickness from the capacitance measurement, measure the capacitance between the shoulder ribs using a capacitance meter, and obtain the thickness from the calibration curve of the capacitance obtained beforehand and the thickness of the subcutaneous fat. Good. In order to obtain the thickness from the measurement of ultrasonic waves, a cross-sectional image between the shoulder ribs is taken using an ultrasonic diagnostic imaging apparatus, and the subcutaneous fat thickness may be obtained. In order to obtain the thickness from the measurement of infrared rays, particularly near infrared rays, the absorption spectrum by the subcutaneous fat between the shoulder ribs is measured using a near infrared irradiation device and a light receiving device, and the absorption spectrum and the subcutaneous fat thickness obtained in advance are measured. What is necessary is just to obtain | require subcutaneous fat thickness from a calibration curve. When CT or MRI is used, the thickness can be obtained directly from the measurement results.

  FIG. 2A shows the relationship between the measurement result of bioimpedance and the measured value of subcutaneous fat between the shoulder ribs. Details of the cats to be measured are as shown in Table 1 below. As is clear from this relationship, it is understood that there is a very high correlation between the bioelectrical impedance and the thickness of subcutaneous fat when the area between the shoulder ribs is selected as the measurement site. On the other hand, FIG. 2 (b) shows the measurement results of bioimpedance at the lumbar region (the part indicated by symbol B in FIG. 1), which is effective for measuring the body fat percentage of dogs, and the measured values of subcutaneous fat. The relationship is shown. This measurement site is a site represented by symbol B in FIG. 1, and this site is biased to the side of 20 mm from the median line in the lower back. In the following description, for the sake of convenience, this measurement site B is also simply referred to as “lumbar region”. As is apparent from the results shown in FIG. 2B, when the lower back is selected as the measurement site, no correlation is recognized between the bioelectrical impedance and the thickness of the subcutaneous fat. The details of the bioimpedance measuring apparatus used for the measurement shown in FIGS. 2A and 2B will be described later.

  FIG. 3A shows the relationship between the body fat percentage of the whole body of the cat and the measured value of subcutaneous fat between the shoulder ribs. As is apparent from this relationship, it is found that when the area between the shoulder ribs is selected as the measurement site, there is a high correlation between the body fat percentage of the whole body and the thickness of the subcutaneous fat. FIG. 3B is a graph showing the relationship between the body fat percentage of the whole body and the bioelectrical impedance based on the results shown in FIG. 2 and the results shown in FIG. As is apparent from the results shown in FIG. 3B, it can be seen that when the area between the shoulder ribs is selected as the measurement site for subcutaneous fat, the body fat percentage of the whole body and the bioimpedance are well correlated. Therefore, the body fat percentage of the whole body can be accurately measured noninvasively by selecting between the shoulder ribs as the measurement site of the thickness of subcutaneous fat according to the method of the present invention.

  As described above, the body fat percentage of the whole body can be obtained by measuring the bioimpedance between the cat's shoulder ribs. Therefore, the bioimpedance measurement result can be directly related to the body fat percentage of the whole body without contrasting the thickness of the subcutaneous fat between the shoulder ribs.

  FIG. 4 (a) shows the relationship between the body fat percentage of the whole body of the cat and the measured value of subcutaneous fat in the lower back. As is clear from this relationship, it can be seen that when the lower back is selected as the measurement site, there is no correlation between the body fat percentage of the whole body and the thickness of the subcutaneous fat. FIG. 4B is a graph showing the relationship between the body fat percentage of the whole body and the bioelectrical impedance based on the results shown in FIG. 2 and the results shown in FIG. 2B described above. As is apparent from the results shown in FIG. 4B, it can be seen that when the lower back is selected as the measurement site for subcutaneous fat, no correlation is found between the body fat percentage of the whole body and the bioelectrical impedance. In other words, it can be understood that the body fat percentage of the whole body cannot be accurately measured even if the waist and back part, which was effective in the case of a dog, is selected as the measurement site for the thickness of subcutaneous fat.

  The above-mentioned whole body fat percentage is measured by the heavy water dilution method. The heavy water dilution method is a well-known method in the art as a method for accurately measuring the body fat percentage of the whole body. However, the heavy water dilution method has a drawback that its measurement is complicated. The details of the heavy water dilution method performed in this specification are as follows.

According to the method ^{1) of} Burkholder et al., 2.5 ml of blood was collected from the jugular vein of each cat (individual Nos. A to F) shown in Table 1 above. The collected blood was subjected to serum separation to obtain a serum sample before heavy water injection. Next, a pterygium needle was placed in the forelimb vein, and heavy water measured by a syringe was injected subcutaneously at a rate of 0.4 g / kg (body weight). Further, 10 ml of hepa raw was injected. The weight of the syringe before and after injection was measured, and the difference was defined as the injection amount of heavy water (W _D2O ) g. The diffusion time of heavy water was 90 minutes. Thereafter, 2.5 ml of blood was again collected from the opposite jugular vein. Serum separation of the collected blood was performed to obtain a serum sample after heavy water injection. The heavy water concentration in the serum samples was analyzed by IRMS. The concentration of heavy water in the serum sample before injection is C ₁ (ppm), the concentration of heavy water after injection is C ₂ (ppm), the amount of injected heavy water is W _D2O (g), and the weight is BW (kg). The body fat percentage was calculated from the following formula.
Body fat percentage (%) = 100− {10 ⁵ W _D2O / (C ₂ −C ₁ )} / 0.732 BW
[1]: William J. Burkholder, Craig D. Thatcher AJVR 59 (8) 1998 927-937

As shown in FIG. 3A, there is a first-order correlation between the body fat percentage of the whole body and the thickness of the subcutaneous fat between the shoulder ribs. That is, if the body fat percentage is z and the thickness of the subcutaneous fat is x, z and x are expressed by the following formula (1): z = a ₁ x + c ₁ (1)
(Wherein a ₁ and c ₁ represent constants).

In the above formula (1), the present inventors have studied to increase the accuracy of measurement in consideration of the contribution of the body weight to the body fat percentage z. When the body weight is y, the body fat percentage z, It was found that the subcutaneous fat thickness x and the body weight y are more accurately described by the following formula (2).
z = a ₂ x + b ₂ y + c ₂ (2)
(Wherein a ₂ , b ₂ and c ₂ represent constants).

For example, when the six cats shown in Table 1 are targeted, the above formula (2) is described by the following formula (2a). In this case, the correlation coefficient R ² is 0.8709. Therefore, it can be seen that the measurement accuracy is improved as compared with the case of FIG. 3A by measuring the body fat percentage based on both the thickness and the weight of the subcutaneous fat.
z = 2.564647x + 2.059329y + 3.634708 (2a)

  FIG. 6 is a perspective view showing an example of a bioimpedance measuring apparatus. The measuring apparatus 10 shown in the figure includes a main body portion 12 and a plurality of electrode bodies 11 that are positioned below the main body portion 12 and hang downward. The electrode body 11 includes two voltage electrodes 13 and two current electrodes 14. Each electrode 13 and 14 is comprised from the electroconductive material. Each of the electrodes 13 and 14 has a cylindrical shape with a rounded tip. The distance between the two voltage electrodes 13 is fixed. Similarly, the distance between the two current electrodes 14 is also fixed. By configuring in this way, fluctuations in the measured impedance value are less likely to occur.

  A control calculator (not shown) is built in the main body 12. The control calculation unit is electrically connected to the electrodes 13 and 14 described above. The control calculation unit 12 incorporates a known control mechanism such as a microcomputer. The control calculation unit 12 incorporates a known impedance measurement circuit. The control calculation unit 12 is configured to allow an alternating current to flow between the two current electrodes 14. The control calculation unit 12 is configured to measure the voltage between the two voltage electrodes 13.

  The control calculation unit 12 can control so that an alternating current of 0.1 to 1 mA flows between the pair of current electrodes 14. Under this energized state, the control calculation unit 12 can measure the voltage between the voltage electrodes 13. The control calculation unit 12 stores in advance data relating to the relationship between the voltage measured by the voltage electrode 13 and the bioelectrical impedance. Based on the measured voltage and data stored in advance, the bioelectrical impedance is displayed on the display unit 15. In some cases, the relationship shown in FIG. 3B can be stored in the control calculation unit 12 and the body fat percentage itself can be displayed on the display unit 15. When the body fat percentage itself is displayed on the display unit 15, the weight of the cat can be input as initial data, and the body fat percentage is calculated according to the above equation (2). You can ask for more.

  The frequency of the alternating current used when measuring the bioimpedance is 80 to 600 kHz, particularly 100 to 500 kHz, and particularly 200 to 400 kHz. This reduces the electric resistance between the electrode and the skin, Even if some hair is sandwiched, it is preferable because it is not easily affected and bioimpedance can be accurately measured.

  When the bioimpedance is measured using the apparatus shown in FIG. 6, as shown in FIG. 7, in any part between the back of the neck and the area between the shoulder ribs along the midline in the prone cat, The hair is divided to expose the skin, and the electrode body 11 of the measuring device 10 is pressed against the exposed skin. Under this state, an alternating current is passed between the current electrodes 14 and the voltage between the voltage electrodes 13 is measured.

  In the measurement, if the cat's body is dirty, it is preferable to remove sebum beforehand. For example, an organic solvent can be applied to remove sebum. The organic solvent can be impregnated with sponge, woven fabric, non-woven fabric, absorbent cotton or the like, and can be used to wipe off the portion against which the electrode body 11 is pressed. As an organic solvent, water-soluble things, such as ethanol and isopropyl alcohol, are used, for example.

  It is also preferable to apply an electrolytic solution to a site where bioimpedance is measured. It is also preferable to apply a conductive cream. This is because the bioimpedance can be accurately measured even when hair that is an insulator exists between the body surface and the electrodes 13 and 14. As the electrolytic solution, for example, an aqueous solution of an electrolyte such as calcium chloride, sodium chloride, or potassium chloride can be used. The concentration of the solute in these electrolytic solutions is preferably 0.03 to 10% by mass, particularly preferably 0.2 to 10% by mass.

DESCRIPTION OF SYMBOLS 10 Bioimpedance measuring apparatus 11 Electrode body 12 Main body part 13 Voltage electrode 14 Current electrode 15 Display part

Claims (5)

  The body fat of a cat, which measures the body fat of the whole body based on the thickness of the subcutaneous fat or its underlying tissue measured at any site between the dorsal neck of the prone cat and between the shoulder ribs Measuring method.   The measurement method according to claim 1, wherein the thickness is measured by bioimpedance, capacitance, ultrasonic waves, infrared rays, CT, or MRI.   The measurement method according to claim 2, wherein the thickness is measured by bioimpedance and an electrolytic solution, a conductive cream, or an organic solvent is applied to a site to be measured.   The measurement method according to any one of claims 1 to 3, wherein the body fat of the entire body is further determined based on the weight of the cat.   A method for measuring the body fat percentage of a cat, wherein the body fat percentage is determined by measuring the bioimpedance between the back of the neck and the shoulder ribs in a prone cat.

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